2019
Duan, Yu; Xiang, Feixiang; Li, Qian; Li, Kaiwen; Grajo, Joseph R; Samir, Anthony E
In: Ultrasound Med Biol, vol. 45, no. 4, pp. 913–920, 2019, ISSN: 1879-291X.
@article{pmid30655110,
title = {Predictive Value of Duplex Ultrasound for Significant In-Stent Restenosis after Percutaneous Transluminal Renal Artery Stent Placement: A Propensity Score Matching Analysis},
author = {Yu Duan and Feixiang Xiang and Qian Li and Kaiwen Li and Joseph R Grajo and Anthony E Samir},
doi = {10.1016/j.ultrasmedbio.2018.11.009},
issn = {1879-291X},
year = {2019},
date = {2019-04-01},
journal = {Ultrasound Med Biol},
volume = {45},
number = {4},
pages = {913--920},
abstract = {To evaluate the value of pre-stenting and early post-stenting (<1 mo) duplex ultrasound parameters in predicting significant in-stent restenosis (ISR), we matched significant ISR patients 1:1 with controls without ISR in pre-stenting and early post-stenting (<1 mo) periods, respectively, using propensity score matching. Duplex ultrasound parameters, such as renal length difference between non-lesion side and lesion side within patient, trans-lesion peak systolic velocity and renal aortic ratio, were compared between cases and controls, and the area under the receiver operating characteristic curve (AUROC) was charted to predict ISR. After propensity score matching, 28 cases were matched in the pre-stenting period and 16 cases in the early post-stenting time period. Pre-stenting renal length difference, early post-stenting peak systolic velocity and renal aortic ratio showed significant differences in case-control comparisons. Early post-stenting peak systolic velocity (AUROC: 0.826, cutoff: 141 cm/s) and renal aortic ratio (AUROC: 0.770, cutoff: 1.75) performed well in predicting significant ISR and may serve as non-invasive markers in ISR surveillance.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
To evaluate the value of pre-stenting and early post-stenting (<1 mo) duplex ultrasound parameters in predicting significant in-stent restenosis (ISR), we matched significant ISR patients 1:1 with controls without ISR in pre-stenting and early post-stenting (<1 mo) periods, respectively, using propensity score matching. Duplex ultrasound parameters, such as renal length difference between non-lesion side and lesion side within patient, trans-lesion peak systolic velocity and renal aortic ratio, were compared between cases and controls, and the area under the receiver operating characteristic curve (AUROC) was charted to predict ISR. After propensity score matching, 28 cases were matched in the pre-stenting period and 16 cases in the early post-stenting time period. Pre-stenting renal length difference, early post-stenting peak systolic velocity and renal aortic ratio showed significant differences in case-control comparisons. Early post-stenting peak systolic velocity (AUROC: 0.826, cutoff: 141 cm/s) and renal aortic ratio (AUROC: 0.770, cutoff: 1.75) performed well in predicting significant ISR and may serve as non-invasive markers in ISR surveillance.
Li, Qian; Yang, Long; Duan, Yu; Xiang, Feixiang; McCarthy, Colin J; Thabet, Ashraf; Cai, Wenli; Grajo, Joseph R; Baikpour, Masoud; McConnell, Roland; White, Phillip J; Samir, Anthony E
A Low-Cost Highly Configurable Phantom for Simulation of Imaging-Guided Endocavitary Procedures Journal Article
In: Ultrasound Q, vol. 35, no. 1, pp. 61–67, 2019, ISSN: 1536-0253.
@article{pmid30601439,
title = {A Low-Cost Highly Configurable Phantom for Simulation of Imaging-Guided Endocavitary Procedures},
author = {Qian Li and Long Yang and Yu Duan and Feixiang Xiang and Colin J McCarthy and Ashraf Thabet and Wenli Cai and Joseph R Grajo and Masoud Baikpour and Roland McConnell and Phillip J White and Anthony E Samir},
doi = {10.1097/RUQ.0000000000000413},
issn = {1536-0253},
year = {2019},
date = {2019-03-01},
journal = {Ultrasound Q},
volume = {35},
number = {1},
pages = {61--67},
abstract = {We developed a method to create customizable phantoms suitable for endocavitary imaging and interventional research, based on the fabrication of an acrylic phantom mold, and development of a phantom matrix composed of gelatin, agar, graphite particles, and propanol. Our phantom was mechanically stable, easily fabricated, and highly adjustable, and its ultrasound (US) and magnetic resonance imaging (MRI) scans showed the qualification for the procedure guidance compared with the human prostate image using the same US system. To test the feasibility of the phantom for the research, the seeds placement guided by MRI/US fusion was performed, and the overall test error (distance from the seed center to the virtual lesion center in olives) was 2.59 ± 0.59 mm. We have created a simple, low-cost, configurable, gelatin-based phantom and tested its feasibility for simulating endorectal interventional US procedures. The design of the phantom mold and matrix is likely to be useful to the broader medical training community, and the preliminary data from the experiment of MRI/US-guided seeds placement showed its potential to test the clinical hypothesis in US research.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We developed a method to create customizable phantoms suitable for endocavitary imaging and interventional research, based on the fabrication of an acrylic phantom mold, and development of a phantom matrix composed of gelatin, agar, graphite particles, and propanol. Our phantom was mechanically stable, easily fabricated, and highly adjustable, and its ultrasound (US) and magnetic resonance imaging (MRI) scans showed the qualification for the procedure guidance compared with the human prostate image using the same US system. To test the feasibility of the phantom for the research, the seeds placement guided by MRI/US fusion was performed, and the overall test error (distance from the seed center to the virtual lesion center in olives) was 2.59 ± 0.59 mm. We have created a simple, low-cost, configurable, gelatin-based phantom and tested its feasibility for simulating endorectal interventional US procedures. The design of the phantom mold and matrix is likely to be useful to the broader medical training community, and the preliminary data from the experiment of MRI/US-guided seeds placement showed its potential to test the clinical hypothesis in US research.
Li, Changtian; Dhyani, Manish; Bhan, Atul K; Grajo, Joseph R; Pratt, Daniel S; Gee, Michael S; Samir, Anthony E
Diagnostic Performance of Shear Wave Elastography in Patients With Autoimmune Liver Disease Journal Article
In: J Ultrasound Med, vol. 38, no. 1, pp. 103–111, 2019, ISSN: 1550-9613.
@article{pmid29761535,
title = {Diagnostic Performance of Shear Wave Elastography in Patients With Autoimmune Liver Disease},
author = {Changtian Li and Manish Dhyani and Atul K Bhan and Joseph R Grajo and Daniel S Pratt and Michael S Gee and Anthony E Samir},
doi = {10.1002/jum.14668},
issn = {1550-9613},
year = {2019},
date = {2019-01-01},
journal = {J Ultrasound Med},
volume = {38},
number = {1},
pages = {103--111},
abstract = {OBJECTIVES: To assess performance of shear wave elastography for evaluation of fibrosis and the histologic stage in patients with autoimmune liver disease (ALD) and to validate previously established advanced fibrosis cutoff values in this cohort.nnMETHODS: Shear wave elastography was performed on patients with ALD with an Aixplorer ultrasound system (SuperSonic Imagine, Aix-en-Provence, France) using an SC6-1 transducer. The median estimated tissue Young modulus was calculated from sets of 8 to 10 elastograms. A blinded, subspecialty-trained pathologist reviewed biopsy specimens. The METAVIR classification was used to stage liver fibrosis and necroinflammation. Steatosis was graded from 0 to 4+. The Kendall τ-b correlation test was performed to identify the correlation between the estimated tissue Young modulus and fibrosis, steatosis, and the necroinflammatory score. The Spearman correlation test was performed to identify the correlation between the estimated tissue Young modulus and clinical data. The diagnostic performance of shear wave elastography for differentiating METAVIR stage F2 or higher from F0 and F1 fibrosis was evaluated by a receiver operating characteristic (ROC) curve analysis.nnRESULTS: Fifty-one patients with ALD were analyzed. The estimated tissue Young modulus was positively correlated with the fibrosis stage and necroinflammation score (r = 0.386; P < .001; r = 0.338; P = .002, respectively) but not steatosis (r = -0.091; P = .527). Serum aspartate aminotransferase, alanine aminotransferase, and total bilirubin values were positively correlated with the estimated tissue Young modulus (r = 0.501; P < .001; r = 0.44; P = .001; r = 0.291; P = .038). The serum albumin value was negatively correlated (r = -0.309; P = .033). The area under the ROC curve was 0.781 (95% confidence interval, 0.641-0.921) for distinguishing F2 or greater fibrosis from F0 and F1 fibrosis. Based on the ROC curve, an optimal cutoff value of 9.15 kPa was identified (sensitivity, 83.3%; specificity, 72.7%).nnCONCLUSIONS: Shear wave elastography is a novel noninvasive adjunct to liver biopsy in evaluation and staging of patients with ALD, showing the potential for serial evaluations of disease progression and treatment responses.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVES: To assess performance of shear wave elastography for evaluation of fibrosis and the histologic stage in patients with autoimmune liver disease (ALD) and to validate previously established advanced fibrosis cutoff values in this cohort.nnMETHODS: Shear wave elastography was performed on patients with ALD with an Aixplorer ultrasound system (SuperSonic Imagine, Aix-en-Provence, France) using an SC6-1 transducer. The median estimated tissue Young modulus was calculated from sets of 8 to 10 elastograms. A blinded, subspecialty-trained pathologist reviewed biopsy specimens. The METAVIR classification was used to stage liver fibrosis and necroinflammation. Steatosis was graded from 0 to 4+. The Kendall τ-b correlation test was performed to identify the correlation between the estimated tissue Young modulus and fibrosis, steatosis, and the necroinflammatory score. The Spearman correlation test was performed to identify the correlation between the estimated tissue Young modulus and clinical data. The diagnostic performance of shear wave elastography for differentiating METAVIR stage F2 or higher from F0 and F1 fibrosis was evaluated by a receiver operating characteristic (ROC) curve analysis.nnRESULTS: Fifty-one patients with ALD were analyzed. The estimated tissue Young modulus was positively correlated with the fibrosis stage and necroinflammation score (r = 0.386; P < .001; r = 0.338; P = .002, respectively) but not steatosis (r = -0.091; P = .527). Serum aspartate aminotransferase, alanine aminotransferase, and total bilirubin values were positively correlated with the estimated tissue Young modulus (r = 0.501; P < .001; r = 0.44; P = .001; r = 0.291; P = .038). The serum albumin value was negatively correlated (r = -0.309; P = .033). The area under the ROC curve was 0.781 (95% confidence interval, 0.641-0.921) for distinguishing F2 or greater fibrosis from F0 and F1 fibrosis. Based on the ROC curve, an optimal cutoff value of 9.15 kPa was identified (sensitivity, 83.3%; specificity, 72.7%).nnCONCLUSIONS: Shear wave elastography is a novel noninvasive adjunct to liver biopsy in evaluation and staging of patients with ALD, showing the potential for serial evaluations of disease progression and treatment responses.
Li, Qian; Lin, Xueying; Zhang, Xi; Samir, Anthony E; Arellano, Ronald S
Imaging-Related Risk Factors for Bleeding Complications of US-Guided Native Renal Biopsy: A Propensity Score Matching Analysis Journal Article
In: J Vasc Interv Radiol, vol. 30, no. 1, pp. 87–94, 2019, ISSN: 1535-7732.
@article{pmid30527649,
title = {Imaging-Related Risk Factors for Bleeding Complications of US-Guided Native Renal Biopsy: A Propensity Score Matching Analysis},
author = {Qian Li and Xueying Lin and Xi Zhang and Anthony E Samir and Ronald S Arellano},
doi = {10.1016/j.jvir.2018.08.031},
issn = {1535-7732},
year = {2019},
date = {2019-01-01},
journal = {J Vasc Interv Radiol},
volume = {30},
number = {1},
pages = {87--94},
abstract = {PURPOSE: To evaluate imaging-related hemorrhagic risk factors for ultrasound (US)-guided native kidney biopsy.nnMATERIALS AND METHODS: A retrospective review was conducted of adult patients who underwent US-guided native kidney biopsy at a single center between January 2006 and March 2016 and identified 37 of 551 patients (6.72%) with postbiopsy bleeding complications, including 11 major complications (2.00%; n = 11) and 26 minor complications (4.72%; n = 26). Ten patients with major complications and 20 with minor complications were matched with 20 control subjects each by propensity score matching based on age, needle size, number of cores, blood pressure, partial thromboplastin time, prothrombin time, platelet count, and estimated glomerular filtration rate.nnRESULTS: Biopsy needle passing through the renal sinus was identified in the patients with major (6 of 10; 60%) and minor complications (8 of 20; 40.0%) but not in the control groups. For patients with major complications, the needle-sinus distance was significantly shorter (5.11 mm ± 7.32 vs 11.14 mm ± 3.54; P = .023) and the needle-capsule distance was significantly longer (17.52 mm ± 8.04 vs 9.28 mm ± 3.29; P = .0004) than in control subjects. The bimodal distribution of cortical tangential angles (< 30° or ≥ 60°) in minor complication cases (17 of 20; 85.0%) was significantly greater than in the control group (8 of 20; 40.0%; odds ratio = 8.50; P = .004).nnCONCLUSIONS: This study identifies imaging risk factors in US-guided native kidney biopsy and recommends an algorithm to manage them, including appropriate needle path position between the renal capsule and sinus and proper needle cortical tangential angle.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: To evaluate imaging-related hemorrhagic risk factors for ultrasound (US)-guided native kidney biopsy.nnMATERIALS AND METHODS: A retrospective review was conducted of adult patients who underwent US-guided native kidney biopsy at a single center between January 2006 and March 2016 and identified 37 of 551 patients (6.72%) with postbiopsy bleeding complications, including 11 major complications (2.00%; n = 11) and 26 minor complications (4.72%; n = 26). Ten patients with major complications and 20 with minor complications were matched with 20 control subjects each by propensity score matching based on age, needle size, number of cores, blood pressure, partial thromboplastin time, prothrombin time, platelet count, and estimated glomerular filtration rate.nnRESULTS: Biopsy needle passing through the renal sinus was identified in the patients with major (6 of 10; 60%) and minor complications (8 of 20; 40.0%) but not in the control groups. For patients with major complications, the needle-sinus distance was significantly shorter (5.11 mm ± 7.32 vs 11.14 mm ± 3.54; P = .023) and the needle-capsule distance was significantly longer (17.52 mm ± 8.04 vs 9.28 mm ± 3.29; P = .0004) than in control subjects. The bimodal distribution of cortical tangential angles (< 30° or ≥ 60°) in minor complication cases (17 of 20; 85.0%) was significantly greater than in the control group (8 of 20; 40.0%; odds ratio = 8.50; P = .004).nnCONCLUSIONS: This study identifies imaging risk factors in US-guided native kidney biopsy and recommends an algorithm to manage them, including appropriate needle path position between the renal capsule and sinus and proper needle cortical tangential angle.
2018
Ozturk, Arinc; Grajo, Joseph R; Gee, Michael S; Benjamin, Alex; Zubajlo, Rebecca E; Thomenius, Kai E; Anthony, Brian W; Samir, Anthony E; Dhyani, Manish
In: Ultrasound Med Biol, vol. 44, no. 12, pp. 2461–2475, 2018, ISSN: 1879-291X.
@article{pmid30232020,
title = {Quantitative Hepatic Fat Quantification in Non-alcoholic Fatty Liver Disease Using Ultrasound-Based Techniques: A Review of Literature and Their Diagnostic Performance},
author = {Arinc Ozturk and Joseph R Grajo and Michael S Gee and Alex Benjamin and Rebecca E Zubajlo and Kai E Thomenius and Brian W Anthony and Anthony E Samir and Manish Dhyani},
doi = {10.1016/j.ultrasmedbio.2018.07.019},
issn = {1879-291X},
year = {2018},
date = {2018-12-01},
journal = {Ultrasound Med Biol},
volume = {44},
number = {12},
pages = {2461--2475},
abstract = {Non-alcoholic fatty liver disease is a condition that is characterized by the presence of >5% fat in the liver and affects more than one billion people worldwide. If adequate and early precautions are not taken, non-alcoholic fatty liver disease can progress to cirrhosis and death. The current reference standard for detecting hepatic steatosis is a liver biopsy. However, because of the potential morbidity associated with liver biopsies, non-invasive imaging biomarkers have been extensively investigated. Magnetic resonance imaging-based methods have proven accuracy in quantifying liver steatosis; however, these techniques are costly and have limited availability. Ultrasound-based quantitative imaging techniques are increasingly utilized because of their widespread availability, ease of use and relative cost-effectiveness. Several ultrasound-based liver fat quantification techniques have been investigated, including techniques that measure changes in the acoustic properties of the liver caused by the presence of fat. In this review, we focus on quantitative ultrasound approaches and their diagnostic performance in the realm of non-alcoholic fatty liver disease.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Non-alcoholic fatty liver disease is a condition that is characterized by the presence of >5% fat in the liver and affects more than one billion people worldwide. If adequate and early precautions are not taken, non-alcoholic fatty liver disease can progress to cirrhosis and death. The current reference standard for detecting hepatic steatosis is a liver biopsy. However, because of the potential morbidity associated with liver biopsies, non-invasive imaging biomarkers have been extensively investigated. Magnetic resonance imaging-based methods have proven accuracy in quantifying liver steatosis; however, these techniques are costly and have limited availability. Ultrasound-based quantitative imaging techniques are increasingly utilized because of their widespread availability, ease of use and relative cost-effectiveness. Several ultrasound-based liver fat quantification techniques have been investigated, including techniques that measure changes in the acoustic properties of the liver caused by the presence of fat. In this review, we focus on quantitative ultrasound approaches and their diagnostic performance in the realm of non-alcoholic fatty liver disease.
Dhyani, Manish; Xiang, Feixiang; Li, Qian; Chen, Luzeng; Li, Changtian; Bhan, Atul K; Anthony, Brian; Grajo, Joseph R; Samir, Anthony E
In: Ultrasound Med Biol, vol. 44, no. 11, pp. 2209–2222, 2018, ISSN: 1879-291X.
@article{pmid30143339,
title = {Ultrasound Shear Wave Elastography: Variations of Liver Fibrosis Assessment as a Function of Depth, Force and Distance from Central Axis of the Transducer with a Comparison of Different Systems},
author = {Manish Dhyani and Feixiang Xiang and Qian Li and Luzeng Chen and Changtian Li and Atul K Bhan and Brian Anthony and Joseph R Grajo and Anthony E Samir},
doi = {10.1016/j.ultrasmedbio.2018.07.003},
issn = {1879-291X},
year = {2018},
date = {2018-11-01},
journal = {Ultrasound Med Biol},
volume = {44},
number = {11},
pages = {2209--2222},
abstract = {We evaluated variation in fibrosis staging caused by depth, pre-load force and measurement off-axis distance on different ultrasound shear wave elastography (SWE) systems prospectively in 20 patients with diffuse liver disease. Shear wave speed (SWS) was measured with transient elastography, acoustic radiation force impulse (ARFI) and 2-D shear wave elastography (SWE). ARFI and 2-D-SWE measurements were obtained at different depths (3, 5 and 7 cm), with different pre-load forces (4, 7 and 10N and variable) and at 0, 2 and 4cm off the central axis of the transducer. A single, blinded pathologist staged fibrosis using the METAVIR system (F0-F4). Area under the receiver operating characteristic curve was charted to differentiate significant fibrosis (F ≥ 2). Depth was the only factor found to influence ARFI-derived values; no acquisition factors were found to affect 2-D-SWE SWS values. ARFI and 2-D-SWE for diagnosis of significant fibrosis at a depth of 7cm along the central axis had good diagnostic performance (areas under the receiver operating characteristic curve: 0.92 and 0.82, respectively), comparable to that of transient elastography. Further investigation of this finding will likely be of interest.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We evaluated variation in fibrosis staging caused by depth, pre-load force and measurement off-axis distance on different ultrasound shear wave elastography (SWE) systems prospectively in 20 patients with diffuse liver disease. Shear wave speed (SWS) was measured with transient elastography, acoustic radiation force impulse (ARFI) and 2-D shear wave elastography (SWE). ARFI and 2-D-SWE measurements were obtained at different depths (3, 5 and 7 cm), with different pre-load forces (4, 7 and 10N and variable) and at 0, 2 and 4cm off the central axis of the transducer. A single, blinded pathologist staged fibrosis using the METAVIR system (F0-F4). Area under the receiver operating characteristic curve was charted to differentiate significant fibrosis (F ≥ 2). Depth was the only factor found to influence ARFI-derived values; no acquisition factors were found to affect 2-D-SWE SWS values. ARFI and 2-D-SWE for diagnosis of significant fibrosis at a depth of 7cm along the central axis had good diagnostic performance (areas under the receiver operating characteristic curve: 0.92 and 0.82, respectively), comparable to that of transient elastography. Further investigation of this finding will likely be of interest.
Li, Qian; Xiang, Feixiang; Lin, Xueying; Grajo, Joseph R; Yang, Long; Xu, Yufeng; Duan, Yu; Vyas, Urvi; Harisinghani, Mukesh; Mahmood, Umar; Samir, Anthony E
The Role of Imaging in Prostate Cancer Care Pathway: Novel Approaches to Urologic Management Challenges Along 10 Imaging Touch Points Journal Article
In: Urology, vol. 119, pp. 23–31, 2018, ISSN: 1527-9995.
@article{pmid29730256,
title = {The Role of Imaging in Prostate Cancer Care Pathway: Novel Approaches to Urologic Management Challenges Along 10 Imaging Touch Points},
author = {Qian Li and Feixiang Xiang and Xueying Lin and Joseph R Grajo and Long Yang and Yufeng Xu and Yu Duan and Urvi Vyas and Mukesh Harisinghani and Umar Mahmood and Anthony E Samir},
doi = {10.1016/j.urology.2018.04.026},
issn = {1527-9995},
year = {2018},
date = {2018-09-01},
journal = {Urology},
volume = {119},
pages = {23--31},
abstract = {We map out a typical prostate cancer care pathway through discussion of updates on modern imaging. Multiparametric magnetic resonance imaging is the most sensitive and specific imaging tool for diagnosis and local staging, but transrectal ultrasound remains the most widely used technique for prostate biopsy guidance. Computed tomography and bone scan are useful in initial staging and recurrence detection. Novel imaging techniques in ultrasound elastography and multiparametric magnetic resonance imaging allow for increased lesion detection sensitivity and have the potential to enhance biopsy, while the development of new positron emission tomography radiotracers has great promise for improved detection of local and metastatic disease in patients with biochemical recurrence.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We map out a typical prostate cancer care pathway through discussion of updates on modern imaging. Multiparametric magnetic resonance imaging is the most sensitive and specific imaging tool for diagnosis and local staging, but transrectal ultrasound remains the most widely used technique for prostate biopsy guidance. Computed tomography and bone scan are useful in initial staging and recurrence detection. Novel imaging techniques in ultrasound elastography and multiparametric magnetic resonance imaging allow for increased lesion detection sensitivity and have the potential to enhance biopsy, while the development of new positron emission tomography radiotracers has great promise for improved detection of local and metastatic disease in patients with biochemical recurrence.
Brattain, Laura J; Telfer, Brian A; Dhyani, Manish; Grajo, Joseph R; Samir, Anthony E
Machine learning for medical ultrasound: status, methods, and future opportunities Journal Article
In: Abdom Radiol (NY), vol. 43, no. 4, pp. 786–799, 2018, ISSN: 2366-0058.
@article{pmid29492605,
title = {Machine learning for medical ultrasound: status, methods, and future opportunities},
author = {Laura J Brattain and Brian A Telfer and Manish Dhyani and Joseph R Grajo and Anthony E Samir},
doi = {10.1007/s00261-018-1517-0},
issn = {2366-0058},
year = {2018},
date = {2018-04-01},
journal = {Abdom Radiol (NY)},
volume = {43},
number = {4},
pages = {786--799},
abstract = {Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modality in the practice of medicine. It is low-cost, non-ionizing, portable, and capable of real-time image acquisition and display. US is a rapidly evolving technology with significant challenges and opportunities. Challenges include high inter- and intra-operator variability and limited image quality control. Tremendous opportunities have arisen in the last decade as a result of exponential growth in available computational power coupled with progressive miniaturization of US devices. As US devices become smaller, enhanced computational capability can contribute significantly to decreasing variability through advanced image processing. In this paper, we review leading machine learning (ML) approaches and research directions in US, with an emphasis on recent ML advances. We also present our outlook on future opportunities for ML techniques to further improve clinical workflow and US-based disease diagnosis and characterization.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modality in the practice of medicine. It is low-cost, non-ionizing, portable, and capable of real-time image acquisition and display. US is a rapidly evolving technology with significant challenges and opportunities. Challenges include high inter- and intra-operator variability and limited image quality control. Tremendous opportunities have arisen in the last decade as a result of exponential growth in available computational power coupled with progressive miniaturization of US devices. As US devices become smaller, enhanced computational capability can contribute significantly to decreasing variability through advanced image processing. In this paper, we review leading machine learning (ML) approaches and research directions in US, with an emphasis on recent ML advances. We also present our outlook on future opportunities for ML techniques to further improve clinical workflow and US-based disease diagnosis and characterization.
2017
Li, Qian; Lin, Xueying; Shao, Yuhong; Xiang, Feixiang; Samir, Anthony E
Imaging and Screening of Thyroid Cancer Journal Article
In: Radiol Clin North Am, vol. 55, no. 6, pp. 1261–1271, 2017, ISSN: 1557-8275.
@article{pmid28991565,
title = {Imaging and Screening of Thyroid Cancer},
author = {Qian Li and Xueying Lin and Yuhong Shao and Feixiang Xiang and Anthony E Samir},
doi = {10.1016/j.rcl.2017.06.002},
issn = {1557-8275},
year = {2017},
date = {2017-11-01},
journal = {Radiol Clin North Am},
volume = {55},
number = {6},
pages = {1261--1271},
abstract = {Ultrasound is the first-line diagnostic tool for diagnosis of thyroid diseases. The low aggressiveness of many thyroid cancers coupled with high sensitivity of sonography can lead to cancer diagnosis and treatment with no effect on outcomes. Ultrasound is recognized as the most important driver of thyroid cancer overdiagnosis. Ultrasound should not be used as a general screening tool and should be reserved for patients at high risk of thyroid cancer and in the diagnostic management of incidentally discovered thyroid nodules. With prescreening risk stratification and application of consensus criteria for nodule biopsy, the value of the diagnostic ultrasound can be maximized.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ultrasound is the first-line diagnostic tool for diagnosis of thyroid diseases. The low aggressiveness of many thyroid cancers coupled with high sensitivity of sonography can lead to cancer diagnosis and treatment with no effect on outcomes. Ultrasound is recognized as the most important driver of thyroid cancer overdiagnosis. Ultrasound should not be used as a general screening tool and should be reserved for patients at high risk of thyroid cancer and in the diagnostic management of incidentally discovered thyroid nodules. With prescreening risk stratification and application of consensus criteria for nodule biopsy, the value of the diagnostic ultrasound can be maximized.
Dhyani, Manish; Grajo, Joseph R; Bhan, Atul K; Corey, Kathleen; Chung, Raymond; Samir, Anthony E
Validation of Shear Wave Elastography Cutoff Values on the Supersonic Aixplorer for Practical Clinical Use in Liver Fibrosis Staging Journal Article
In: Ultrasound Med Biol, vol. 43, no. 6, pp. 1125–1133, 2017, ISSN: 1879-291X.
@article{pmid28341490,
title = {Validation of Shear Wave Elastography Cutoff Values on the Supersonic Aixplorer for Practical Clinical Use in Liver Fibrosis Staging},
author = {Manish Dhyani and Joseph R Grajo and Atul K Bhan and Kathleen Corey and Raymond Chung and Anthony E Samir},
doi = {10.1016/j.ultrasmedbio.2017.01.022},
issn = {1879-291X},
year = {2017},
date = {2017-06-01},
journal = {Ultrasound Med Biol},
volume = {43},
number = {6},
pages = {1125--1133},
abstract = {The purpose of this study was to determine the validity of previously established ultrasound shear wave elastography (SWE) cut-off values (≥F2 fibrosis) on an independent cohort of patients with chronic liver disease. In this cross-sectional study, approved by the institutional review board and compliant with the Health Insurance Portability and Accountability Act, 338 patients undergoing liver biopsy underwent SWE using an Aixplorer ultrasound machine (SuperSonic Imagine, Aix-en-Provence, France). Median SWE values were calculated from sets of 10 elastograms. A single blinded pathologist evaluated METAVIR fibrosis staging as the gold standard. The study analyzed 277 patients with a mean age of 48 y. On pathologic examination, 212 patients (76.5%) had F0-F1 fibrosis, whereas 65 (23.5%) had ≥F2 fibrosis. Spearman's correlation of fibrosis with SWE was 0.456 (p < 0.001). A cut-off value of 7.29 kPa yielded sensitivity of 95.4% and specificity of 50.5% for the diagnosis of METAVIR stage ≥F2 liver fibrosis in patients with liver disease using the SuperSonic Imagine Aixplorer SWE system.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The purpose of this study was to determine the validity of previously established ultrasound shear wave elastography (SWE) cut-off values (≥F2 fibrosis) on an independent cohort of patients with chronic liver disease. In this cross-sectional study, approved by the institutional review board and compliant with the Health Insurance Portability and Accountability Act, 338 patients undergoing liver biopsy underwent SWE using an Aixplorer ultrasound machine (SuperSonic Imagine, Aix-en-Provence, France). Median SWE values were calculated from sets of 10 elastograms. A single blinded pathologist evaluated METAVIR fibrosis staging as the gold standard. The study analyzed 277 patients with a mean age of 48 y. On pathologic examination, 212 patients (76.5%) had F0-F1 fibrosis, whereas 65 (23.5%) had ≥F2 fibrosis. Spearman's correlation of fibrosis with SWE was 0.456 (p < 0.001). A cut-off value of 7.29 kPa yielded sensitivity of 95.4% and specificity of 50.5% for the diagnosis of METAVIR stage ≥F2 liver fibrosis in patients with liver disease using the SuperSonic Imagine Aixplorer SWE system.
Li, Qian; Vij, Abhinav; Hahn, Peter F; Xiang, Feixiang; Samir, Anthony E
The Value of Active Ultrasound Surveillance for Patients With Small Testicular Lesions Journal Article
In: Ultrasound Q, vol. 33, no. 1, pp. 23–27, 2017, ISSN: 1536-0253.
@article{pmid27575843,
title = {The Value of Active Ultrasound Surveillance for Patients With Small Testicular Lesions},
author = {Qian Li and Abhinav Vij and Peter F Hahn and Feixiang Xiang and Anthony E Samir},
doi = {10.1097/RUQ.0000000000000245},
issn = {1536-0253},
year = {2017},
date = {2017-03-01},
journal = {Ultrasound Q},
volume = {33},
number = {1},
pages = {23--27},
abstract = {This study aimed to determine whether active ultrasound surveillance may obviate the need for surgical resection in selected patients with small testicular lesions (STLs). A retrospective 11-year review was conducted of adults who were diagnosed with an STL on scrotal ultrasonography and who either had orchiectomy or sonographic follow-up during a period of at least 3 months. A total of 101 subjects were enrolled. Ultrasound findings, clinical features, histopathology/follow-up imaging were recorded. Logistic regression analysis was performed to select independent risk factors for the diagnosis of malignancy. Seventeen (16.8%) subjects underwent immediate surgery, 8 (7.9%) of 101 underwent surgery after ultrasound follow-up, and 76 (75.3%) of 101 were followed with ultrasound only. The follow-up period ranged from 1 to 7 months in the 8 patients who ultimately underwent surgery after ultrasound follow-up and from 6 to 84 months in the 76 patients followed up with ultrasound only. All 15 malignant cases underwent immediate surgery without follow-up sonography. The frequency of lesions, either benign at surgery or stable on ultrasound, was 85.1% (86 of 101; 95% confidence interval, 77%-91%). Logistic regression analysis showed that lesion size was the only independent risk factor for malignancy in hypoechoic STLs (P < 0.05). Most of the STLs were stable on serial sonograms and likely benign. Active ultrasound surveillance may be an appropriate management strategy in patients with STLs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study aimed to determine whether active ultrasound surveillance may obviate the need for surgical resection in selected patients with small testicular lesions (STLs). A retrospective 11-year review was conducted of adults who were diagnosed with an STL on scrotal ultrasonography and who either had orchiectomy or sonographic follow-up during a period of at least 3 months. A total of 101 subjects were enrolled. Ultrasound findings, clinical features, histopathology/follow-up imaging were recorded. Logistic regression analysis was performed to select independent risk factors for the diagnosis of malignancy. Seventeen (16.8%) subjects underwent immediate surgery, 8 (7.9%) of 101 underwent surgery after ultrasound follow-up, and 76 (75.3%) of 101 were followed with ultrasound only. The follow-up period ranged from 1 to 7 months in the 8 patients who ultimately underwent surgery after ultrasound follow-up and from 6 to 84 months in the 76 patients followed up with ultrasound only. All 15 malignant cases underwent immediate surgery without follow-up sonography. The frequency of lesions, either benign at surgery or stable on ultrasound, was 85.1% (86 of 101; 95% confidence interval, 77%-91%). Logistic regression analysis showed that lesion size was the only independent risk factor for malignancy in hypoechoic STLs (P < 0.05). Most of the STLs were stable on serial sonograms and likely benign. Active ultrasound surveillance may be an appropriate management strategy in patients with STLs.
2015
Li, Qian; Chen, Lei; Halpern, Elkan F; Samir, Anthony E
Detection and Measurement of Stones With Ultrasound Strain Elastography: A Phantom Study Journal Article
In: Ultrasound Q, vol. 31, no. 4, pp. 272–278, 2015, ISSN: 1536-0253.
@article{pmid26656990,
title = {Detection and Measurement of Stones With Ultrasound Strain Elastography: A Phantom Study},
author = {Qian Li and Lei Chen and Elkan F Halpern and Anthony E Samir},
doi = {10.1097/RUQ.0000000000000204},
issn = {1536-0253},
year = {2015},
date = {2015-12-01},
journal = {Ultrasound Q},
volume = {31},
number = {4},
pages = {272--278},
abstract = {The sonoelastographic appearances of stones in a phantom were evaluated in this study. Ten stones were embedded into a tissue-mimicking meat phantom. The stone axial (vertical) and transverse (horizontal) dimensions measured by an electronic digital caliper, gray-scale ultrasound, and strain elastography (SE) were compared in 5 groups with stones embedded at different depths. In this study, physically measured axial and transverse stone dimensions were 1.17 to 6.86 and 1.30 to 11.15 mm, respectively. Strain elastography showed a characteristic 3-layer pattern associated with stones, comprising a superficial transition region, a hard region, and a deep transition region. As SE data were available in group 5, only data of groups 1 to 4 were analyzed. Compared with physical measurements, measurement mean errors of SE horizontal and SE vertical dimensions ranged from -0.20 to 0.42 mm and from -1.28 to -0.05 mm, respectively, in the 4 groups. Paired t testing demonstrated a significant horizontal dimension measurement error difference between B mode and SE method in group 4 (0.44 vs -0.20 mm, P < 0.05; F = 1.18, P > 0.05), but not in the other groups. Strain elastography horizontal dimension measurement error was not statistically correlated with stone size in the 4 groups. Strain elastography vertical dimension measurement error significantly correlated with stone size only in group 4 (P < 0.05). Preliminary results indicate that stone horizontal and vertical dimensions can be measured using SE in a soft tissue phantom, including when shadowing precludes measurement of vertical dimension on conventional 2-dimensional ultrasound. These results provide substantial motivation to further investigate SE as a modality to image stones in clinical practice.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The sonoelastographic appearances of stones in a phantom were evaluated in this study. Ten stones were embedded into a tissue-mimicking meat phantom. The stone axial (vertical) and transverse (horizontal) dimensions measured by an electronic digital caliper, gray-scale ultrasound, and strain elastography (SE) were compared in 5 groups with stones embedded at different depths. In this study, physically measured axial and transverse stone dimensions were 1.17 to 6.86 and 1.30 to 11.15 mm, respectively. Strain elastography showed a characteristic 3-layer pattern associated with stones, comprising a superficial transition region, a hard region, and a deep transition region. As SE data were available in group 5, only data of groups 1 to 4 were analyzed. Compared with physical measurements, measurement mean errors of SE horizontal and SE vertical dimensions ranged from -0.20 to 0.42 mm and from -1.28 to -0.05 mm, respectively, in the 4 groups. Paired t testing demonstrated a significant horizontal dimension measurement error difference between B mode and SE method in group 4 (0.44 vs -0.20 mm, P < 0.05; F = 1.18, P > 0.05), but not in the other groups. Strain elastography horizontal dimension measurement error was not statistically correlated with stone size in the 4 groups. Strain elastography vertical dimension measurement error significantly correlated with stone size only in group 4 (P < 0.05). Preliminary results indicate that stone horizontal and vertical dimensions can be measured using SE in a soft tissue phantom, including when shadowing precludes measurement of vertical dimension on conventional 2-dimensional ultrasound. These results provide substantial motivation to further investigate SE as a modality to image stones in clinical practice.
Samir, Anthony E; Dhyani, Manish; Anvari, Arash; Prescott, Jason; Halpern, Elkan F; Faquin, William C; Stephen, Antonia
In: Radiology, vol. 277, no. 2, pp. 565–573, 2015, ISSN: 1527-1315.
@article{pmid25955578,
title = {Shear-Wave Elastography for the Preoperative Risk Stratification of Follicular-patterned Lesions of the Thyroid: Diagnostic Accuracy and Optimal Measurement Plane},
author = {Anthony E Samir and Manish Dhyani and Arash Anvari and Jason Prescott and Elkan F Halpern and William C Faquin and Antonia Stephen},
doi = {10.1148/radiol.2015141627},
issn = {1527-1315},
year = {2015},
date = {2015-11-01},
journal = {Radiology},
volume = {277},
number = {2},
pages = {565--573},
abstract = {PURPOSE: To evaluate the diagnostic accuracy of shear-wave elastography (SWE) for the diagnosis of malignancy in follicular lesions and to identify the optimal SWE measurement plane.nnMATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant, single-institution, prospective pilot study. Subjects scheduled for surgery after a previous fine-needle aspiration report of "atypia of undetermined significance" or "follicular lesion of undetermined significance," "suspicion for follicular neoplasm," or "suspicion for Hurthle cell neoplasm," were enrolled after obtaining informed consent. Subjects underwent conventional ultrasonography (US), Doppler evaluation, and SWE preoperatively, and their predictive value for thyroid malignancy was evaluated relative to the reference standard of surgical pathologic findings.nnRESULTS: Thirty-five patients (12 men, 23 women) with a mean age of 55 years (range, 23-85 years) and a fine-needle aspiration diagnosis of atypia of undetermined significance or follicular lesion of undetermined significance (n = 16), suspicion for follicular neoplasm (n = 14), and suspicion for Hurthle cell neoplasm (n = 5) were enrolled in the study. Male sex was a statistically significant (P = .02) predictor of malignancy, but age was not. No sonographic morphologic parameter, including nodule size, microcalcification, macrocalcification, halo sign, taller than wide dimension, or hypoechogenicity, was associated with malignancy. Similarly, no Doppler feature, including intranodular vascularity, pulsatility index, resistive index, or peak-systolic velocity, was associated with malignancy. Higher median SWE tissue Young modulus estimates from the transverse insonation plane were associated with malignancy, yielding an area under the receiver operating characteristic curve of 0.81 (95% confidence interval: 0.62, 1.00) for differentiation of malignant from benign nodules. At a cutoff value of 22.3 kPa, sensitivity, specificity, positive predictive value, and negative predictive value of 82%, 88%, 75%, and 91%, respectively, were observed.nnCONCLUSION: This prospective pilot study indicates that SWE may be a valuable tool in preoperative malignancy risk assessment of follicular-patterned thyroid nodules.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: To evaluate the diagnostic accuracy of shear-wave elastography (SWE) for the diagnosis of malignancy in follicular lesions and to identify the optimal SWE measurement plane.nnMATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant, single-institution, prospective pilot study. Subjects scheduled for surgery after a previous fine-needle aspiration report of "atypia of undetermined significance" or "follicular lesion of undetermined significance," "suspicion for follicular neoplasm," or "suspicion for Hurthle cell neoplasm," were enrolled after obtaining informed consent. Subjects underwent conventional ultrasonography (US), Doppler evaluation, and SWE preoperatively, and their predictive value for thyroid malignancy was evaluated relative to the reference standard of surgical pathologic findings.nnRESULTS: Thirty-five patients (12 men, 23 women) with a mean age of 55 years (range, 23-85 years) and a fine-needle aspiration diagnosis of atypia of undetermined significance or follicular lesion of undetermined significance (n = 16), suspicion for follicular neoplasm (n = 14), and suspicion for Hurthle cell neoplasm (n = 5) were enrolled in the study. Male sex was a statistically significant (P = .02) predictor of malignancy, but age was not. No sonographic morphologic parameter, including nodule size, microcalcification, macrocalcification, halo sign, taller than wide dimension, or hypoechogenicity, was associated with malignancy. Similarly, no Doppler feature, including intranodular vascularity, pulsatility index, resistive index, or peak-systolic velocity, was associated with malignancy. Higher median SWE tissue Young modulus estimates from the transverse insonation plane were associated with malignancy, yielding an area under the receiver operating characteristic curve of 0.81 (95% confidence interval: 0.62, 1.00) for differentiation of malignant from benign nodules. At a cutoff value of 22.3 kPa, sensitivity, specificity, positive predictive value, and negative predictive value of 82%, 88%, 75%, and 91%, respectively, were observed.nnCONCLUSION: This prospective pilot study indicates that SWE may be a valuable tool in preoperative malignancy risk assessment of follicular-patterned thyroid nodules.
Trifanov, Dmitry S; Dhyani, Manish; Bledsoe, Jacob R; Misdraji, Joseph; Bhan, Atul K; Chung, Raymond T; Samir, Anthony E
Amyloidosis of the liver on shear wave elastography: case report and review of literature Journal Article
In: Abdom Imaging, vol. 40, no. 8, pp. 3078–3083, 2015, ISSN: 1432-0509.
@article{pmid26254907,
title = {Amyloidosis of the liver on shear wave elastography: case report and review of literature},
author = {Dmitry S Trifanov and Manish Dhyani and Jacob R Bledsoe and Joseph Misdraji and Atul K Bhan and Raymond T Chung and Anthony E Samir},
doi = {10.1007/s00261-015-0519-4},
issn = {1432-0509},
year = {2015},
date = {2015-10-01},
journal = {Abdom Imaging},
volume = {40},
number = {8},
pages = {3078--3083},
abstract = {Amyloidosis is extremely rare, with an estimated 2225 new US cases reported annually. Signs and symptoms of the disease are subtle and imaging findings are not pathognomonic. Currently, diagnosis requires biopsy to demonstrate the deposition of amyloid. Elastography is a new imaging modality that evaluates tissue elasticity. It has shown to have efficacy in characterizing thyroid nodules, detecting prostate cancer, and staging liver fibrosis. We present a case of hepatic amyloidosis in a 51-year-old male that demonstrates significantly increased stiffness with a median value of 99.1 kPa (range 25.7-188.9 kPa) on shear-wave elastography (SWE) imaging, which is significantly higher than the cut-off range reported for cirrhosis on SWE (10.4-11.5 kPa). This finding raises the possibility that elastographic imaging may be sensitive to tissue mechanical changes induced by amyloid deposition.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Amyloidosis is extremely rare, with an estimated 2225 new US cases reported annually. Signs and symptoms of the disease are subtle and imaging findings are not pathognomonic. Currently, diagnosis requires biopsy to demonstrate the deposition of amyloid. Elastography is a new imaging modality that evaluates tissue elasticity. It has shown to have efficacy in characterizing thyroid nodules, detecting prostate cancer, and staging liver fibrosis. We present a case of hepatic amyloidosis in a 51-year-old male that demonstrates significantly increased stiffness with a median value of 99.1 kPa (range 25.7-188.9 kPa) on shear-wave elastography (SWE) imaging, which is significantly higher than the cut-off range reported for cirrhosis on SWE (10.4-11.5 kPa). This finding raises the possibility that elastographic imaging may be sensitive to tissue mechanical changes induced by amyloid deposition.
Flynn, Aidan; Li, Qian; Panagia, Marcello; Abdelbaky, Amr; MacNabb, Megan; Samir, Anthony; Cypess, Aaron M; Weyman, Arthur E; Tawakol, Ahmed; Scherrer-Crosbie, Marielle
Contrast-Enhanced Ultrasound: A Novel Noninvasive, Nonionizing Method for the Detection of Brown Adipose Tissue in Humans Journal Article
In: J Am Soc Echocardiogr, vol. 28, no. 10, pp. 1247–1254, 2015, ISSN: 1097-6795.
@article{pmid26255029,
title = {Contrast-Enhanced Ultrasound: A Novel Noninvasive, Nonionizing Method for the Detection of Brown Adipose Tissue in Humans},
author = {Aidan Flynn and Qian Li and Marcello Panagia and Amr Abdelbaky and Megan MacNabb and Anthony Samir and Aaron M Cypess and Arthur E Weyman and Ahmed Tawakol and Marielle Scherrer-Crosbie},
doi = {10.1016/j.echo.2015.06.014},
issn = {1097-6795},
year = {2015},
date = {2015-10-01},
journal = {J Am Soc Echocardiogr},
volume = {28},
number = {10},
pages = {1247--1254},
abstract = {BACKGROUND: Brown adipose tissue (BAT) consumes glucose when it is activated by cold exposure, allowing its detection in humans by (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) with computed tomography (CT). The investigators recently described a novel noninvasive and nonionizing imaging method to assess BAT in mice using contrast-enhanced ultrasound (CEUS). Here, they report the application of this method in healthy humans.nnMETHODS: Thirteen healthy volunteers were recruited. CEUS was performed before and after cold exposure in all subjects using a continuous intravenous infusion of perflutren gas-filled lipid microbubbles and triggered imaging of the supraclavicular space. The first five subjects received microbubbles at a lower infusion rate than the subsequent eight subjects and were analyzed as a separate group. Blood flow was estimated as the product of the plateau (A) and the slope (β) of microbubble replenishment curves. All underwent (18)F-FDG PET/CT after cold exposure.nnRESULTS: An increase in the acoustic signal was noted in the supraclavicular adipose tissue area with increasing triggering intervals in all subjects, demonstrating the presence of blood flow. The area imaged by CEUS colocalized with BAT, as detected by ¹⁸F-FDG PET/CT. In a cohort of eight subjects with an optimized CEUS protocol, CEUS-derived BAT blood flow increased with cold exposure compared with basal BAT blood flow in warm conditions (median Aβ = 3.3 AU/s [interquartile range, 0.5-5.7 AU/s] vs 1.25 AU/s [interquartile range, 0.5-2.6 AU/s]; P = .02). Of these eight subjects, five had greater than twofold increases in blood flow after cold exposure; these responders had higher BAT activity measured by (18)F-FDG PET/CT (median maximal standardized uptake value, 2.25 [interquartile range, 1.53-4.57] vs 0.51 [interquartile range, 0.47-0.73]; P = .02).nnCONCLUSIONS: The present study demonstrates the feasibility of using CEUS as a noninvasive, nonionizing imaging modality in estimating BAT blood flow in young, healthy humans. CEUS may be a useful and scalable tool in the assessment of BAT and BAT-targeted therapies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Brown adipose tissue (BAT) consumes glucose when it is activated by cold exposure, allowing its detection in humans by (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) with computed tomography (CT). The investigators recently described a novel noninvasive and nonionizing imaging method to assess BAT in mice using contrast-enhanced ultrasound (CEUS). Here, they report the application of this method in healthy humans.nnMETHODS: Thirteen healthy volunteers were recruited. CEUS was performed before and after cold exposure in all subjects using a continuous intravenous infusion of perflutren gas-filled lipid microbubbles and triggered imaging of the supraclavicular space. The first five subjects received microbubbles at a lower infusion rate than the subsequent eight subjects and were analyzed as a separate group. Blood flow was estimated as the product of the plateau (A) and the slope (β) of microbubble replenishment curves. All underwent (18)F-FDG PET/CT after cold exposure.nnRESULTS: An increase in the acoustic signal was noted in the supraclavicular adipose tissue area with increasing triggering intervals in all subjects, demonstrating the presence of blood flow. The area imaged by CEUS colocalized with BAT, as detected by ¹⁸F-FDG PET/CT. In a cohort of eight subjects with an optimized CEUS protocol, CEUS-derived BAT blood flow increased with cold exposure compared with basal BAT blood flow in warm conditions (median Aβ = 3.3 AU/s [interquartile range, 0.5-5.7 AU/s] vs 1.25 AU/s [interquartile range, 0.5-2.6 AU/s]; P = .02). Of these eight subjects, five had greater than twofold increases in blood flow after cold exposure; these responders had higher BAT activity measured by (18)F-FDG PET/CT (median maximal standardized uptake value, 2.25 [interquartile range, 1.53-4.57] vs 0.51 [interquartile range, 0.47-0.73]; P = .02).nnCONCLUSIONS: The present study demonstrates the feasibility of using CEUS as a noninvasive, nonionizing imaging modality in estimating BAT blood flow in young, healthy humans. CEUS may be a useful and scalable tool in the assessment of BAT and BAT-targeted therapies.
Zhu, Qing-Li; Faquin, William C; Samir, Anthony E
In: AJR Am J Roentgenol, vol. 205, no. 4, pp. 861–865, 2015, ISSN: 1546-3141.
@article{pmid26397337,
title = {Relationship Between Sonographic Characteristics and Afirma Gene Expression Classifier Results in Thyroid Nodules With Indeterminate Fine-Needle Aspiration Cytopathology},
author = {Qing-Li Zhu and William C Faquin and Anthony E Samir},
doi = {10.2214/AJR.14.13984},
issn = {1546-3141},
year = {2015},
date = {2015-10-01},
journal = {AJR Am J Roentgenol},
volume = {205},
number = {4},
pages = {861--865},
abstract = {OBJECTIVE: The purpose of this article is to investigate whether specific clinical and sonographic characteristics are predictive of a benign Afirma test result.nnMATERIALS AND METHODS: We conducted a retrospective study of Afirma gene expression classifier analysis performed in 44 patients with 45 indeterminate thyroid fine-needle aspiration (FNA) cytologic results between March 2013 and April 2014. Of these, 33 of 45 nodules (73.3%) were repeat atypia of undetermined significance (AUS) and follicular lesions of undetermined significance (FLUS), or follicular neoplasm (FN) and suspicious for a follicular neoplasm (SFN) before Afirma testing.nnRESULTS: Of the 45 nodules, 21 (46.7%) were cytologically diagnosed as FLUS, 16 (35.6%) were diagnosed as AUS, and eight (17.8%) were diagnosed as FN or SFN. By Afirma testing, 23 of the 45 nodules (51.1%) were benign, 21 (46.7%) were suspicious, and one (2.2%) had nondiagnostic results. The mean (± SD) nodule size was smaller in the Afirma-benign group than in the Afirma-suspicious group (1.8 ± 0.8 cm [95% CI, 1.4-2.1] vs 2.2 ± 0.8 cm [95% CI, 1.8-2.6]; p < 0.035). No sonographic feature was statistically significantly different between the Afirma-benign and -suspicious groups, including nodule solidity (p = 0.225), echogenicity (p = 0.543), calcification (p = 0.542), and hypervascularity (p = 0.976). All nodules were ovoid shaped and had circumscribed margins in both Afirma groups.nnCONCLUSION: Smaller nodule size was the only characteristic associated with a benign diagnosis on Afirma testing. Sonographic characteristics are not helpful in cases that had a repeat indeterminate FNA finding before Afirma testing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVE: The purpose of this article is to investigate whether specific clinical and sonographic characteristics are predictive of a benign Afirma test result.nnMATERIALS AND METHODS: We conducted a retrospective study of Afirma gene expression classifier analysis performed in 44 patients with 45 indeterminate thyroid fine-needle aspiration (FNA) cytologic results between March 2013 and April 2014. Of these, 33 of 45 nodules (73.3%) were repeat atypia of undetermined significance (AUS) and follicular lesions of undetermined significance (FLUS), or follicular neoplasm (FN) and suspicious for a follicular neoplasm (SFN) before Afirma testing.nnRESULTS: Of the 45 nodules, 21 (46.7%) were cytologically diagnosed as FLUS, 16 (35.6%) were diagnosed as AUS, and eight (17.8%) were diagnosed as FN or SFN. By Afirma testing, 23 of the 45 nodules (51.1%) were benign, 21 (46.7%) were suspicious, and one (2.2%) had nondiagnostic results. The mean (± SD) nodule size was smaller in the Afirma-benign group than in the Afirma-suspicious group (1.8 ± 0.8 cm [95% CI, 1.4-2.1] vs 2.2 ± 0.8 cm [95% CI, 1.8-2.6]; p < 0.035). No sonographic feature was statistically significantly different between the Afirma-benign and -suspicious groups, including nodule solidity (p = 0.225), echogenicity (p = 0.543), calcification (p = 0.542), and hypervascularity (p = 0.976). All nodules were ovoid shaped and had circumscribed margins in both Afirma groups.nnCONCLUSION: Smaller nodule size was the only characteristic associated with a benign diagnosis on Afirma testing. Sonographic characteristics are not helpful in cases that had a repeat indeterminate FNA finding before Afirma testing.
Samir, Anthony E; Allegretti, Andrew S; Zhu, Qingli; Dhyani, Manish; Anvari, Arash; Sullivan, Dorothy A; Trottier, Caitlin A; Dougherty, Sarah; Williams, Winfred W; Babitt, Jodie L; Wenger, Julia; Thadhani, Ravi I; Lin, Herbert Y
Shear wave elastography in chronic kidney disease: a pilot experience in native kidneys Journal Article
In: BMC Nephrol, vol. 16, pp. 119, 2015, ISSN: 1471-2369.
@article{pmid26227484,
title = {Shear wave elastography in chronic kidney disease: a pilot experience in native kidneys},
author = {Anthony E Samir and Andrew S Allegretti and Qingli Zhu and Manish Dhyani and Arash Anvari and Dorothy A Sullivan and Caitlin A Trottier and Sarah Dougherty and Winfred W Williams and Jodie L Babitt and Julia Wenger and Ravi I Thadhani and Herbert Y Lin},
doi = {10.1186/s12882-015-0120-7},
issn = {1471-2369},
year = {2015},
date = {2015-07-01},
journal = {BMC Nephrol},
volume = {16},
pages = {119},
abstract = {BACKGROUND: There currently is a need for a non-invasive measure of renal fibrosis. We aim to explore whether shear wave elastography (SWE)-derived estimates of tissue stiffness may serve as a non-invasive biomarker that can distinguish normal and abnormal renal parenchymal tissue.nnMETHODS: Participants with CKD (by estimated GFR) and healthy volunteers underwent SWE. Renal elasticity was estimated as Young's modulus (YM) in kilopascals (kPa). Univariate Wilcoxon rank-sum tests were used.nnRESULTS: Twenty-five participants with CKD (median GFR 38 mL/min; quartile 1, quartile 3 28, 42) and 20 healthy controls without CKD underwent SWE performed by a single radiologist. CKD was associated with increased median YM (9.40 [5.55, 22.35] vs. 4.40 [3.68, 5.70] kPa; p = 0.002) and higher median intra-subject inter-measurement estimated YM's variability (4.27 [2.89, 9.90] vs. 1.51 [1.21, 2.05] kPa; p < 0.001).nnCONCLUSIONS: SWE-derived estimates of renal stiffness and intra-subject estimated stiffness variability are higher in patients with CKD than in healthy controls. Renal fibrosis is a plausible explanation for the observed difference in YM. Further studies are required to determine the relationship between YM, estimated renal stiffness, and renal fibrosis severity.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: There currently is a need for a non-invasive measure of renal fibrosis. We aim to explore whether shear wave elastography (SWE)-derived estimates of tissue stiffness may serve as a non-invasive biomarker that can distinguish normal and abnormal renal parenchymal tissue.nnMETHODS: Participants with CKD (by estimated GFR) and healthy volunteers underwent SWE. Renal elasticity was estimated as Young's modulus (YM) in kilopascals (kPa). Univariate Wilcoxon rank-sum tests were used.nnRESULTS: Twenty-five participants with CKD (median GFR 38 mL/min; quartile 1, quartile 3 28, 42) and 20 healthy controls without CKD underwent SWE performed by a single radiologist. CKD was associated with increased median YM (9.40 [5.55, 22.35] vs. 4.40 [3.68, 5.70] kPa; p = 0.002) and higher median intra-subject inter-measurement estimated YM's variability (4.27 [2.89, 9.90] vs. 1.51 [1.21, 2.05] kPa; p < 0.001).nnCONCLUSIONS: SWE-derived estimates of renal stiffness and intra-subject estimated stiffness variability are higher in patients with CKD than in healthy controls. Renal fibrosis is a plausible explanation for the observed difference in YM. Further studies are required to determine the relationship between YM, estimated renal stiffness, and renal fibrosis severity.
Dhyani, Manish; Anvari, Arash; Samir, Anthony E
Ultrasound elastography: liver Journal Article
In: Abdom Imaging, vol. 40, no. 4, pp. 698–708, 2015, ISSN: 1432-0509.
@article{pmid25690689,
title = {Ultrasound elastography: liver},
author = {Manish Dhyani and Arash Anvari and Anthony E Samir},
doi = {10.1007/s00261-015-0373-4},
issn = {1432-0509},
year = {2015},
date = {2015-04-01},
journal = {Abdom Imaging},
volume = {40},
number = {4},
pages = {698--708},
abstract = {Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical practice to aid the diagnosis and management of diffuse liver disease. Elastography has been shown to be capable of differentiating advanced and early-stage liver fibrosis, and consequently a major application in clinical liver care includes progression to cirrhosis risk stratification through (1) assessment of liver fibrosis stage in HCV and HBV patients, (2) distinguishing non-alcoholic steatohepatitis from simple steatosis in non-alcoholic fatty liver disease patients, and (3) prognostic evaluation of liver disease is autoimmune liver disease. In addition, elastographic characterization of focal liver lesions and evaluation of clinically significant portal hypertension have the potential to be clinically useful and are areas of active clinical research.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical practice to aid the diagnosis and management of diffuse liver disease. Elastography has been shown to be capable of differentiating advanced and early-stage liver fibrosis, and consequently a major application in clinical liver care includes progression to cirrhosis risk stratification through (1) assessment of liver fibrosis stage in HCV and HBV patients, (2) distinguishing non-alcoholic steatohepatitis from simple steatosis in non-alcoholic fatty liver disease patients, and (3) prognostic evaluation of liver disease is autoimmune liver disease. In addition, elastographic characterization of focal liver lesions and evaluation of clinically significant portal hypertension have the potential to be clinically useful and are areas of active clinical research.
Anvari, Arash; Barr, Richard G; Dhyani, Manish; Samir, Anthony E
Clinical application of sonoelastography in thyroid, prostate, kidney, pancreas, and deep venous thrombosis Journal Article
In: Abdom Imaging, vol. 40, no. 4, pp. 709–722, 2015, ISSN: 1432-0509.
@article{pmid25750099,
title = {Clinical application of sonoelastography in thyroid, prostate, kidney, pancreas, and deep venous thrombosis},
author = {Arash Anvari and Richard G Barr and Manish Dhyani and Anthony E Samir},
doi = {10.1007/s00261-015-0383-2},
issn = {1432-0509},
year = {2015},
date = {2015-04-01},
journal = {Abdom Imaging},
volume = {40},
number = {4},
pages = {709--722},
abstract = {This article reviews the clinical applications of current ultrasound elastography methods in non-hepatic conditions including thyroid nodules, prostate cancer, chronic kidney disease, solid renal lesions, pancreatic lesions, and deep vein thrombosis. Pathophysiology alters tissue mechanical properties via ultrastructural changes including fibrosis, increased cellularity, bleeding, and necrosis, creating a target biomarker, which can be imaged qualitatively or quantitatively with US elastography. US elastography methods can add information to conventional US methods and improve the diagnostic performance of conventional US in a range of disease processes.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This article reviews the clinical applications of current ultrasound elastography methods in non-hepatic conditions including thyroid nodules, prostate cancer, chronic kidney disease, solid renal lesions, pancreatic lesions, and deep vein thrombosis. Pathophysiology alters tissue mechanical properties via ultrastructural changes including fibrosis, increased cellularity, bleeding, and necrosis, creating a target biomarker, which can be imaged qualitatively or quantitatively with US elastography. US elastography methods can add information to conventional US methods and improve the diagnostic performance of conventional US in a range of disease processes.
Sheth, Rahul A; Arellano, Ronald S; Uppot, Raul N; Samir, Anthony E; Goyal, Lipika; Zhu, Andrew X; Gervais, Debra A; Mahmood, Umar
Prospective trial with optical molecular imaging for percutaneous interventions in focal hepatic lesions Journal Article
In: Radiology, vol. 274, no. 3, pp. 917–926, 2015, ISSN: 1527-1315.
@article{pmid25302707,
title = {Prospective trial with optical molecular imaging for percutaneous interventions in focal hepatic lesions},
author = {Rahul A Sheth and Ronald S Arellano and Raul N Uppot and Anthony E Samir and Lipika Goyal and Andrew X Zhu and Debra A Gervais and Umar Mahmood},
doi = {10.1148/radiol.14141308},
issn = {1527-1315},
year = {2015},
date = {2015-03-01},
journal = {Radiology},
volume = {274},
number = {3},
pages = {917--926},
abstract = {PURPOSE: To demonstrate the clinical translation of optical molecular imaging (OMI) for the localization of focal hepatic lesions during percutaneous hepatic interventions.nnMATERIALS AND METHODS: Institutional review board approval was obtained for this prospective, single-center, HIPAA-compliant trial. Patients who were suspected of having hepatocellular carcinoma or liver metastases from colorectal cancer and were scheduled for percutaneous liver biopsy or thermal ablation were eligible for this study. Patients (n = 5) received 0.5 mg per kilogram of body weight of indocyanine green (ICG) intravenously 24 hours prior to their scheduled procedure in this study. Intraprocedurally, a handheld device composed of an endoscope that fits coaxially through a standard 17-gauge introducer needle was advanced into the liver, and real-time measurements of ICG fluorescence were obtained. A point-of-care fluorescence imaging system was used to image ICG fluorescence in biopsy samples. Target-to-background ratios (TBRs) were calculated by dividing the mean fluorescence intensity in the lesion by the mean fluorescence intensity in the adjacent liver parenchyma. The reference standard for determination of proper needle positioning in patients undergoing biopsy was final pathologic analysis of biopsy specimens or follow-up imaging.nnRESULTS: Intraprocedural OMI was successfully performed in six lesions (two lesions in patient 3) in five patients. The median size of the targeted lesions was 16 mm (range, 10-21 mm). Four of five biopsies (80%) yielded an accurate pathologic diagnosis, and one biopsy specimen showed benign liver parenchyma; both ablated lesions showed no residual disease 1 month after the procedure. The median overall added procedure time to perform OMI was 2 minutes. ICG was found to localize with TBRs greater than 2.0 (median, 7.9; range, 2.4-13.4) in all target lesions. No trial-related adverse events were reported.nnCONCLUSION: The clinical translation of OMI to percutaneous hepatic interventions was demonstrated.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: To demonstrate the clinical translation of optical molecular imaging (OMI) for the localization of focal hepatic lesions during percutaneous hepatic interventions.nnMATERIALS AND METHODS: Institutional review board approval was obtained for this prospective, single-center, HIPAA-compliant trial. Patients who were suspected of having hepatocellular carcinoma or liver metastases from colorectal cancer and were scheduled for percutaneous liver biopsy or thermal ablation were eligible for this study. Patients (n = 5) received 0.5 mg per kilogram of body weight of indocyanine green (ICG) intravenously 24 hours prior to their scheduled procedure in this study. Intraprocedurally, a handheld device composed of an endoscope that fits coaxially through a standard 17-gauge introducer needle was advanced into the liver, and real-time measurements of ICG fluorescence were obtained. A point-of-care fluorescence imaging system was used to image ICG fluorescence in biopsy samples. Target-to-background ratios (TBRs) were calculated by dividing the mean fluorescence intensity in the lesion by the mean fluorescence intensity in the adjacent liver parenchyma. The reference standard for determination of proper needle positioning in patients undergoing biopsy was final pathologic analysis of biopsy specimens or follow-up imaging.nnRESULTS: Intraprocedural OMI was successfully performed in six lesions (two lesions in patient 3) in five patients. The median size of the targeted lesions was 16 mm (range, 10-21 mm). Four of five biopsies (80%) yielded an accurate pathologic diagnosis, and one biopsy specimen showed benign liver parenchyma; both ablated lesions showed no residual disease 1 month after the procedure. The median overall added procedure time to perform OMI was 2 minutes. ICG was found to localize with TBRs greater than 2.0 (median, 7.9; range, 2.4-13.4) in all target lesions. No trial-related adverse events were reported.nnCONCLUSION: The clinical translation of OMI to percutaneous hepatic interventions was demonstrated.
Samir, Anthony E; Dhyani, Manish; Vij, Abhinav; Bhan, Atul K; Halpern, Elkan F; Méndez-Navarro, Jorge; Corey, Kathleen E; Chung, Raymond T
Shear-wave elastography for the estimation of liver fibrosis in chronic liver disease: determining accuracy and ideal site for measurement Journal Article
In: Radiology, vol. 274, no. 3, pp. 888–896, 2015, ISSN: 1527-1315.
@article{pmid25393946,
title = {Shear-wave elastography for the estimation of liver fibrosis in chronic liver disease: determining accuracy and ideal site for measurement},
author = {Anthony E Samir and Manish Dhyani and Abhinav Vij and Atul K Bhan and Elkan F Halpern and Jorge Méndez-Navarro and Kathleen E Corey and Raymond T Chung},
doi = {10.1148/radiol.14140839},
issn = {1527-1315},
year = {2015},
date = {2015-03-01},
journal = {Radiology},
volume = {274},
number = {3},
pages = {888--896},
abstract = {PURPOSE: To evaluate the accuracy of shear-wave elastography (SWE) for staging liver fibrosis in patients with diffuse liver disease (including patients with hepatitis C virus [HCV]) and to determine the relative accuracy of SWE measurements obtained from different hepatic acquisition sites for staging liver fibrosis.nnMATERIALS AND METHODS: The institutional review board approved this single-institution prospective study, which was performed between January 2010 and March 2013 in 136 consecutive patients who underwent SWE before their scheduled liver biopsy (age range, 18-76 years; mean age, 49 years; 70 men, 66 women). Informed consent was obtained from all patients. SWE measurements were obtained at four sites in the liver. Biopsy specimens were reviewed in a blinded manner by a pathologist using METAVIR criteria. SWE measurements and biopsy results were compared by using the Spearman correlation and receiver operating characteristic (ROC) curve analysis.nnRESULTS: SWE values obtained at the upper right lobe showed the highest correlation with estimation of fibrosis (r = 0.41, P < .001). Inflammation and steatosis did not show any correlation with SWE values except for values from the left lobe, which showed correlation with steatosis (r = 0.24, P = .004). The area under the ROC curve (AUC) in the differentiation of stage F2 fibrosis or greater, stage F3 fibrosis or greater, and stage F4 fibrosis was 0.77 (95% confidence interval [CI]: 0.68, 0.86), 0.82 (95% CI: 0.75, 0.91), and 0.82 (95% CI: 0.70, 0.95), respectively, for all subjects who underwent liver biopsy. The corresponding AUCs for the subset of patients with HCV were 0.80 (95% CI: 0.67, 0.92), 0.82 (95% CI: 0.70, 0.95), and 0.89 (95% CI: 0.73, 1.00). The adjusted AUCs for differentiating stage F2 or greater fibrosis in patients with chronic liver disease and those with HCV were 0.84 and 0.87, respectively.nnCONCLUSION: SWE estimates of liver stiffness obtained from the right upper lobe showed the best correlation with liver fibrosis severity and can potentially be used as a noninvasive test to differentiate intermediate degrees of liver fibrosis in patients with liver disease.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: To evaluate the accuracy of shear-wave elastography (SWE) for staging liver fibrosis in patients with diffuse liver disease (including patients with hepatitis C virus [HCV]) and to determine the relative accuracy of SWE measurements obtained from different hepatic acquisition sites for staging liver fibrosis.nnMATERIALS AND METHODS: The institutional review board approved this single-institution prospective study, which was performed between January 2010 and March 2013 in 136 consecutive patients who underwent SWE before their scheduled liver biopsy (age range, 18-76 years; mean age, 49 years; 70 men, 66 women). Informed consent was obtained from all patients. SWE measurements were obtained at four sites in the liver. Biopsy specimens were reviewed in a blinded manner by a pathologist using METAVIR criteria. SWE measurements and biopsy results were compared by using the Spearman correlation and receiver operating characteristic (ROC) curve analysis.nnRESULTS: SWE values obtained at the upper right lobe showed the highest correlation with estimation of fibrosis (r = 0.41, P < .001). Inflammation and steatosis did not show any correlation with SWE values except for values from the left lobe, which showed correlation with steatosis (r = 0.24, P = .004). The area under the ROC curve (AUC) in the differentiation of stage F2 fibrosis or greater, stage F3 fibrosis or greater, and stage F4 fibrosis was 0.77 (95% confidence interval [CI]: 0.68, 0.86), 0.82 (95% CI: 0.75, 0.91), and 0.82 (95% CI: 0.70, 0.95), respectively, for all subjects who underwent liver biopsy. The corresponding AUCs for the subset of patients with HCV were 0.80 (95% CI: 0.67, 0.92), 0.82 (95% CI: 0.70, 0.95), and 0.89 (95% CI: 0.73, 1.00). The adjusted AUCs for differentiating stage F2 or greater fibrosis in patients with chronic liver disease and those with HCV were 0.84 and 0.87, respectively.nnCONCLUSION: SWE estimates of liver stiffness obtained from the right upper lobe showed the best correlation with liver fibrosis severity and can potentially be used as a noninvasive test to differentiate intermediate degrees of liver fibrosis in patients with liver disease.
Anvari, Arash; Forsberg, Flemming; Samir, Anthony E
A Primer on the Physical Principles of Tissue Harmonic Imaging Journal Article
In: Radiographics, vol. 35, no. 7, pp. 1955–1964, 2015, ISSN: 1527-1323.
@article{pmid26562232,
title = {A Primer on the Physical Principles of Tissue Harmonic Imaging},
author = {Arash Anvari and Flemming Forsberg and Anthony E Samir},
doi = {10.1148/rg.2015140338},
issn = {1527-1323},
year = {2015},
date = {2015-01-01},
journal = {Radiographics},
volume = {35},
number = {7},
pages = {1955--1964},
abstract = {Tissue harmonic imaging (THI) is a routinely used component of diagnostic ultrasonography (US). In this method, higher-frequency harmonic waves produced by nonlinear fundamental US wave propagation are used to generate images that contain fewer artifacts than those seen on conventional fundamental wave US tissue imaging. Harmonic frequencies are integer multiples of the fundamental frequency. The majority of current clinical US systems use second harmonic echoes for THI image formation. Image processing techniques (ie, bandwidth receive filtering, pulse inversion, side-by-side phase cancellation, and pulse-coded harmonics) are used to eliminate the fundamental frequency echoes, and the remaining harmonic frequency data are used to generate the diagnostic image. Advantages of THI include improved signal-to-noise ratio and reduced artifacts produced by side lobes, grating lobes, and reverberation. THI has been accepted in US practice, and variations of the technology are available on most US systems typically used for diagnostic imaging in radiologic practice. Differential THI is a further improvement that combines the advantages of THI, including superior tissue definition and reduced speckle artifact, with the greater penetration of lower frequency US, which permits high-quality harmonic imaging at greater depth than could previously be performed with conventional THI.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tissue harmonic imaging (THI) is a routinely used component of diagnostic ultrasonography (US). In this method, higher-frequency harmonic waves produced by nonlinear fundamental US wave propagation are used to generate images that contain fewer artifacts than those seen on conventional fundamental wave US tissue imaging. Harmonic frequencies are integer multiples of the fundamental frequency. The majority of current clinical US systems use second harmonic echoes for THI image formation. Image processing techniques (ie, bandwidth receive filtering, pulse inversion, side-by-side phase cancellation, and pulse-coded harmonics) are used to eliminate the fundamental frequency echoes, and the remaining harmonic frequency data are used to generate the diagnostic image. Advantages of THI include improved signal-to-noise ratio and reduced artifacts produced by side lobes, grating lobes, and reverberation. THI has been accepted in US practice, and variations of the technology are available on most US systems typically used for diagnostic imaging in radiologic practice. Differential THI is a further improvement that combines the advantages of THI, including superior tissue definition and reduced speckle artifact, with the greater penetration of lower frequency US, which permits high-quality harmonic imaging at greater depth than could previously be performed with conventional THI.
2013
Dhyani, Manish; Faquin, William; Lubitz, Carrie C; Daniels, Gilbert H; Samir, Anthony E
In: AJR Am J Roentgenol, vol. 201, no. 6, pp. 1335–1339, 2013, ISSN: 1546-3141.
@article{pmid24261375,
title = {How to interpret thyroid fine-needle aspiration biopsy reports: a guide for the busy radiologist in the era of the Bethesda Classification System},
author = {Manish Dhyani and William Faquin and Carrie C Lubitz and Gilbert H Daniels and Anthony E Samir},
doi = {10.2214/AJR.13.10537},
issn = {1546-3141},
year = {2013},
date = {2013-12-01},
journal = {AJR Am J Roentgenol},
volume = {201},
number = {6},
pages = {1335--1339},
abstract = {OBJECTIVE: Fine-needle aspiration biopsy (FNAB) is the current primary test to risk stratify thyroid nodules. However, in up to one third of biopsies, cytology is indeterminate. The Bethesda System for Reporting Thyroid Cytopathology categorizes thyroid cytology findings into six groups, with each group assigned a putative malignancy risk. This article reviews the Bethesda System, emphasizing the key facts necessary to understand thyroid biopsy results and effectively manage patients after FNAB.nnCONCLUSION: It is important to diagnose and stratify the risk of malignancy in thyroid nodules. A working knowledge of the Bethesda System permits accurate, evidence-based risk stratification of patients with thyroid nodules and thereby facilitates their management. Because it is a uniform diagnostic approach, the Bethesda System allows comparisons of different management strategies across different institutions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVE: Fine-needle aspiration biopsy (FNAB) is the current primary test to risk stratify thyroid nodules. However, in up to one third of biopsies, cytology is indeterminate. The Bethesda System for Reporting Thyroid Cytopathology categorizes thyroid cytology findings into six groups, with each group assigned a putative malignancy risk. This article reviews the Bethesda System, emphasizing the key facts necessary to understand thyroid biopsy results and effectively manage patients after FNAB.nnCONCLUSION: It is important to diagnose and stratify the risk of malignancy in thyroid nodules. A working knowledge of the Bethesda System permits accurate, evidence-based risk stratification of patients with thyroid nodules and thereby facilitates their management. Because it is a uniform diagnostic approach, the Bethesda System allows comparisons of different management strategies across different institutions.
2012
Li, Qian; Samir, Anthony E
Echinococcal cysts of the liver and spleen: complex hepatic and splenic cystic lesions Journal Article
In: Ultrasound Q, vol. 28, no. 3, pp. 205–207, 2012, ISSN: 1536-0253.
@article{pmid22902848,
title = {Echinococcal cysts of the liver and spleen: complex hepatic and splenic cystic lesions},
author = {Qian Li and Anthony E Samir},
doi = {10.1097/RUQ.0b013e318262cd49},
issn = {1536-0253},
year = {2012},
date = {2012-09-01},
journal = {Ultrasound Q},
volume = {28},
number = {3},
pages = {205--207},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lubitz, Carrie C; Nagarkatti, Sushruta S; Faquin, William C; Samir, Anthony E; Hassan, Maria C; Barbesino, Giuseppe; Ross, Douglas S; Randolph, Gregory W; Gaz, Randall D; Stephen, Antonia E; Hodin, Richard A; Daniels, Gilbert H; Parangi, Sareh
Diagnostic yield of nondiagnostic thyroid nodules is not altered by timing of repeat biopsy Journal Article
In: Thyroid, vol. 22, no. 6, pp. 590–594, 2012, ISSN: 1557-9077.
@article{pmid22667452,
title = {Diagnostic yield of nondiagnostic thyroid nodules is not altered by timing of repeat biopsy},
author = {Carrie C Lubitz and Sushruta S Nagarkatti and William C Faquin and Anthony E Samir and Maria C Hassan and Giuseppe Barbesino and Douglas S Ross and Gregory W Randolph and Randall D Gaz and Antonia E Stephen and Richard A Hodin and Gilbert H Daniels and Sareh Parangi},
doi = {10.1089/thy.2011.0442},
issn = {1557-9077},
year = {2012},
date = {2012-06-01},
journal = {Thyroid},
volume = {22},
number = {6},
pages = {590--594},
abstract = {BACKGROUND: Guidelines from the National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference recommend a repeat fine-needle aspiration biopsy (FNAB) after 3 months for thyroid nodules with a nondiagnostic (ND) result. Our aims were to assess which factors influenced their clinical management and to determine if the timing of the repeat FNAB affects the diagnostic yield.nnMETHODS: A retrospective institutional review of 298 patients from 1/2006 to 12/2007 with an ND FNAB was performed. The factors influencing the next step in management, including age, gender, history of radiation, presence of Hashimoto's thyroiditis, thyroid-stimulating hormone levels, and ultrasound characteristics, were evaluated. The effect of the time of the repeat FNABs on their diagnostic yield was assessed.nnRESULTS: Of the 298 patients in our cohort, 9% were referred directly for surgery, 76% had a repeat FNAB, and 15% were observed. Tumor size was the only independent variable correlated with treatment strategy after a ND FNAB. There was not a significant difference in diagnostic yields between repeat FNABs performed earlier than 3 months compared to those preformed later (p=0.58).nnCONCLUSION: The timing of repeat FNAB for an initial ND FNAB does not affect diagnostic yield of the repeat FNAB.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Guidelines from the National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference recommend a repeat fine-needle aspiration biopsy (FNAB) after 3 months for thyroid nodules with a nondiagnostic (ND) result. Our aims were to assess which factors influenced their clinical management and to determine if the timing of the repeat FNAB affects the diagnostic yield.nnMETHODS: A retrospective institutional review of 298 patients from 1/2006 to 12/2007 with an ND FNAB was performed. The factors influencing the next step in management, including age, gender, history of radiation, presence of Hashimoto's thyroiditis, thyroid-stimulating hormone levels, and ultrasound characteristics, were evaluated. The effect of the time of the repeat FNABs on their diagnostic yield was assessed.nnRESULTS: Of the 298 patients in our cohort, 9% were referred directly for surgery, 76% had a repeat FNAB, and 15% were observed. Tumor size was the only independent variable correlated with treatment strategy after a ND FNAB. There was not a significant difference in diagnostic yields between repeat FNABs performed earlier than 3 months compared to those preformed later (p=0.58).nnCONCLUSION: The timing of repeat FNAB for an initial ND FNAB does not affect diagnostic yield of the repeat FNAB.
Samir, Anthony E; Vij, Abhinav; Seale, Melanie K; Desai, Gaurav; Halpern, Elkan; Faquin, William C; Parangi, Sareh; Hahn, Peter F; Daniels, Gilbert H
Ultrasound-guided percutaneous thyroid nodule core biopsy: clinical utility in patients with prior nondiagnostic fine-needle aspirate Journal Article
In: Thyroid, vol. 22, no. 5, pp. 461–467, 2012, ISSN: 1557-9077.
@article{pmid22304390,
title = {Ultrasound-guided percutaneous thyroid nodule core biopsy: clinical utility in patients with prior nondiagnostic fine-needle aspirate},
author = {Anthony E Samir and Abhinav Vij and Melanie K Seale and Gaurav Desai and Elkan Halpern and William C Faquin and Sareh Parangi and Peter F Hahn and Gilbert H Daniels},
doi = {10.1089/thy.2011.0061},
issn = {1557-9077},
year = {2012},
date = {2012-05-01},
journal = {Thyroid},
volume = {22},
number = {5},
pages = {461--467},
abstract = {BACKGROUND: Five percent to 20% of thyroid nodule fine-needle aspiration (FNA) samples are nondiagnostic. The objective of this study was to determine whether a combination of FNA and core biopsy (CFNACB) would yield a higher proportion of diagnostic readings compared with FNA alone in patients with a history of one or more prior nondiagnostic FNA readings.nnMETHODS: We conducted a retrospective study of 90 core biopsies (CBs) performed in 82 subjects (55 women and 27 men) between 2006 and 2008 in an outpatient clinic.nnRESULTS: CFNACB yielded a diagnostic reading in 87%. The diagnostic reading yield of the CB component of CFNACB was significantly superior to the concurrent FNA component, with CB yielding a diagnosis in 77% of cases and FNA yielding a diagnosis in 47% (p<0.0001). The combination of CB and FNA had a higher diagnostic reading yield than either alone. In 69 nodules that had only one prior nondiagnostic FNA, CB was diagnostic in 74%, FNA was diagnostic in 52%, CFNACB was diagnostic in 87%, and CB performed significantly better than FNA (p=0.0135). In 21 nodules with two or more prior nondiagnostic FNAs, CFNACB and CB were diagnostic in 86%, FNA was diagnostic in 29%, and CB was significantly better than FNA (p=0.0005). Clinical, ultrasound, or histopathologic follow-up was available for 81% (73/90) of the CFNACB procedures. No subject with a benign CFNACB reading was diagnosed with thyroid malignancy in the follow-up period (range 4-37 months, mean 18 months), although one subject had minimal increase in nodule size and was awaiting repeat sonography at study conclusion.nnCONCLUSION: Thyroid nodule CFNACB is safe and clinically useful in selected patients when a prior FNA reading is nondiagnostic. CFNACB is superior to either CB or FNA alone. CFNACB should be strongly considered as an alternative to surgery in individuals with two prior nondiagnostic FNAs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Five percent to 20% of thyroid nodule fine-needle aspiration (FNA) samples are nondiagnostic. The objective of this study was to determine whether a combination of FNA and core biopsy (CFNACB) would yield a higher proportion of diagnostic readings compared with FNA alone in patients with a history of one or more prior nondiagnostic FNA readings.nnMETHODS: We conducted a retrospective study of 90 core biopsies (CBs) performed in 82 subjects (55 women and 27 men) between 2006 and 2008 in an outpatient clinic.nnRESULTS: CFNACB yielded a diagnostic reading in 87%. The diagnostic reading yield of the CB component of CFNACB was significantly superior to the concurrent FNA component, with CB yielding a diagnosis in 77% of cases and FNA yielding a diagnosis in 47% (p<0.0001). The combination of CB and FNA had a higher diagnostic reading yield than either alone. In 69 nodules that had only one prior nondiagnostic FNA, CB was diagnostic in 74%, FNA was diagnostic in 52%, CFNACB was diagnostic in 87%, and CB performed significantly better than FNA (p=0.0135). In 21 nodules with two or more prior nondiagnostic FNAs, CFNACB and CB were diagnostic in 86%, FNA was diagnostic in 29%, and CB was significantly better than FNA (p=0.0005). Clinical, ultrasound, or histopathologic follow-up was available for 81% (73/90) of the CFNACB procedures. No subject with a benign CFNACB reading was diagnosed with thyroid malignancy in the follow-up period (range 4-37 months, mean 18 months), although one subject had minimal increase in nodule size and was awaiting repeat sonography at study conclusion.nnCONCLUSION: Thyroid nodule CFNACB is safe and clinically useful in selected patients when a prior FNA reading is nondiagnostic. CFNACB is superior to either CB or FNA alone. CFNACB should be strongly considered as an alternative to surgery in individuals with two prior nondiagnostic FNAs.
Kambadakone, Avinash; Arasu, Vignesh A; Samir, Anthony E; Eisner, Brian H; Kulkarni, Naveen M; Hahn, Peter F; Sahani, Dushyant V
Qualitative assessment of enhancement in a renal mass: contribution of subtraction CT Journal Article
In: J Comput Assist Tomogr, vol. 36, no. 4, pp. 381–387, 2012, ISSN: 1532-3145.
@article{pmid22805664,
title = {Qualitative assessment of enhancement in a renal mass: contribution of subtraction CT},
author = {Avinash Kambadakone and Vignesh A Arasu and Anthony E Samir and Brian H Eisner and Naveen M Kulkarni and Peter F Hahn and Dushyant V Sahani},
doi = {10.1097/RCT.0b013e318256b1ba},
issn = {1532-3145},
year = {2012},
date = {2012-01-01},
journal = {J Comput Assist Tomogr},
volume = {36},
number = {4},
pages = {381--387},
abstract = {PURPOSE: To evaluate the impact of subtraction CT on reader confidence and diagnostic accuracy when characterizing renal masses.nnMATERIALS AND METHODS: In this institutional review board-approved retrospective study, 159 patients (85 men and 74 women; mean age, 62.6 years; range, 22-88 years) underwent routine unenhanced and contrast-enhanced multidetector computed tomography (MDCT) for renal lesion characterization. Subtraction images were subsequently generated on scanner console. Two readers independently reviewed the MDCT images to characterize presence of enhancement using a 6-point scale during 3 blinded review sessions of (1) only subtraction, (2) routine, and (3) combined subtraction and routine images. The standard of reference consisted of either histopathology or follow-up imaging and clinical data.nnRESULTS: Of the 240 lesions evaluated, 60 lesions (mean, 3.2 cm; range, 1-7.5 cm) were enhancing and 180 lesions (mean, 2.7 cm; range, 0.5-12 cm) were nonenhancing. For determination of lesion enhancement, a combined evaluation of routine MDCT and subtraction images improved reader confidence in 60% to 63% of lesions (P < 0.001). The combined evaluation also provided the highest sensitivity (97%), specificity (99%), and accuracy (98.9%).nnCONCLUSION: When used in combination with routine image interpretation, subtraction CT improves reader confidence and diagnostic accuracy in identifying enhancement in renal lesions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: To evaluate the impact of subtraction CT on reader confidence and diagnostic accuracy when characterizing renal masses.nnMATERIALS AND METHODS: In this institutional review board-approved retrospective study, 159 patients (85 men and 74 women; mean age, 62.6 years; range, 22-88 years) underwent routine unenhanced and contrast-enhanced multidetector computed tomography (MDCT) for renal lesion characterization. Subtraction images were subsequently generated on scanner console. Two readers independently reviewed the MDCT images to characterize presence of enhancement using a 6-point scale during 3 blinded review sessions of (1) only subtraction, (2) routine, and (3) combined subtraction and routine images. The standard of reference consisted of either histopathology or follow-up imaging and clinical data.nnRESULTS: Of the 240 lesions evaluated, 60 lesions (mean, 3.2 cm; range, 1-7.5 cm) were enhancing and 180 lesions (mean, 2.7 cm; range, 0.5-12 cm) were nonenhancing. For determination of lesion enhancement, a combined evaluation of routine MDCT and subtraction images improved reader confidence in 60% to 63% of lesions (P < 0.001). The combined evaluation also provided the highest sensitivity (97%), specificity (99%), and accuracy (98.9%).nnCONCLUSION: When used in combination with routine image interpretation, subtraction CT improves reader confidence and diagnostic accuracy in identifying enhancement in renal lesions.
2011
Boland, Giles W L; Thrall, James H; Gazelle, G Scott; Samir, Anthony; Rosenthal, Daniel I; Dreyer, Keith J; Alkasab, Tarik K
Decision support for radiologist report recommendations Journal Article
In: J Am Coll Radiol, vol. 8, no. 12, pp. 819–823, 2011, ISSN: 1558-349X.
@article{pmid22136994,
title = {Decision support for radiologist report recommendations},
author = {Giles W L Boland and James H Thrall and G Scott Gazelle and Anthony Samir and Daniel I Rosenthal and Keith J Dreyer and Tarik K Alkasab},
doi = {10.1016/j.jacr.2011.08.003},
issn = {1558-349X},
year = {2011},
date = {2011-12-01},
journal = {J Am Coll Radiol},
volume = {8},
number = {12},
pages = {819--823},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2010
Liu, Chang-Hsien; Arellano, Ronald S; Uppot, Raul N; Samir, Anthony E; Gervais, Debra A; Mueller, Peter R
Radiofrequency ablation of hepatic tumours: effect of post-ablation margin on local tumour progression Journal Article
In: Eur Radiol, vol. 20, no. 4, pp. 877–885, 2010, ISSN: 1432-1084.
@article{pmid19760232,
title = {Radiofrequency ablation of hepatic tumours: effect of post-ablation margin on local tumour progression},
author = {Chang-Hsien Liu and Ronald S Arellano and Raul N Uppot and Anthony E Samir and Debra A Gervais and Peter R Mueller},
doi = {10.1007/s00330-009-1610-4},
issn = {1432-1084},
year = {2010},
date = {2010-04-01},
journal = {Eur Radiol},
volume = {20},
number = {4},
pages = {877--885},
abstract = {PURPOSE: The purpose of this study was to retrospectively evaluate the relationship between post-ablation margins and local tumour progression following radiofrequency ablation (RFA) of hepatocellular carcinomas and colorectal liver metastases.nnMETHODS: Eighty-three patients with 107 hepatic tumours who underwent RFA were divided into two groups: the hepatocellular carcinoma (HCC) group (55 patients with 69 lesions) and the colorectal liver metastases group (28 patients with 38 lesions). Post-ablation margins were calculated on 1-month follow-up contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) studies. Efficacy was evaluated at 1-month post-ablation, then at 3-month intervals for the first year and biannually thereafter.nnRESULTS: The results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.020) and tumour size smaller than 2.5 cm (P = 0.001) significantly correlated with local control for the HCC group. In the colorectal liver metastases group, the results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.345) and tumour size smaller than 2.5 cm (P = 0.168) did not correlate with local control.nnCONCLUSION: Percutaneous RFA is more effective in achieving local control in patients with HCCs than with colorectal liver metastases.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: The purpose of this study was to retrospectively evaluate the relationship between post-ablation margins and local tumour progression following radiofrequency ablation (RFA) of hepatocellular carcinomas and colorectal liver metastases.nnMETHODS: Eighty-three patients with 107 hepatic tumours who underwent RFA were divided into two groups: the hepatocellular carcinoma (HCC) group (55 patients with 69 lesions) and the colorectal liver metastases group (28 patients with 38 lesions). Post-ablation margins were calculated on 1-month follow-up contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) studies. Efficacy was evaluated at 1-month post-ablation, then at 3-month intervals for the first year and biannually thereafter.nnRESULTS: The results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.020) and tumour size smaller than 2.5 cm (P = 0.001) significantly correlated with local control for the HCC group. In the colorectal liver metastases group, the results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.345) and tumour size smaller than 2.5 cm (P = 0.168) did not correlate with local control.nnCONCLUSION: Percutaneous RFA is more effective in achieving local control in patients with HCCs than with colorectal liver metastases.
2009
Baier, Nina D; Hahn, Peter F; Gervais, Debra A; Samir, Anthony; Halpern, Elkan F; Mueller, Peter R; Harisinghani, Mukesh G
Fine-needle aspiration biopsy of thyroid nodules: experience in a cohort of 944 patients Journal Article
In: AJR Am J Roentgenol, vol. 193, no. 4, pp. 1175–1179, 2009, ISSN: 1546-3141.
@article{pmid19770344,
title = {Fine-needle aspiration biopsy of thyroid nodules: experience in a cohort of 944 patients},
author = {Nina D Baier and Peter F Hahn and Debra A Gervais and Anthony Samir and Elkan F Halpern and Peter R Mueller and Mukesh G Harisinghani},
doi = {10.2214/AJR.08.1840},
issn = {1546-3141},
year = {2009},
date = {2009-10-01},
journal = {AJR Am J Roentgenol},
volume = {193},
number = {4},
pages = {1175--1179},
abstract = {OBJECTIVE: The objective of our study was to determine the likelihood of malignancy in thyroid nodules and the risk of a nondiagnostic fine-needle aspiration biopsy (FNAB) on the basis of the demographic characteristics of the patients and sonographic features of the nodules.nnMATERIALS AND METHODS: Between January 2002 and November 2007, 2,338 ultrasound-guided thyroid, thyroid bed, and cervical lymph node FNABs were performed at a tertiary referral center. Entry criteria for our retrospective study were adult patients who underwent thyroid nodule FNAB and had previously undergone diagnostic sonography. From previous reports for 944 thyroid nodules (739 nodules in women and 205 nodules in men), four sonographic features were recorded: longest dimension, morphology, presence of microcalcifications, and presence of lymphadenopathy. The final diagnosis of each nodule was classified as benign, malignant, or nondiagnostic on the basis of surgical pathology when available and cytology otherwise and was analyzed for correlation with individual sonographic features and combinations of features.nnRESULTS: The prevalence of malignancy and of nondiagnostic FNAB in this study was 11.0% and 11.8%, respectively. Statistically significant (p < 0.05) findings in malignant nodules were younger patient age (< or = 45 years; odds ratio [OR], 1.54) and solid nodule morphology (OR, 2.38). The significant predictors of a nondiagnostic-quality FNAB were older patient age (> 75 years; OR, 1.95) and a nodule > or = 10 mm (OR, 1.45). Adding information about the other evaluated ultrasound features did not lead to a significant result.nnCONCLUSION: Malignant thyroid nodules tend to be solid (86.5%). Patients older than 75 years showed a clearly increased risk of nondiagnostic FNAB, but to predict a higher risk of malignancy or of nondiagnostic FNAB using ultrasound remains difficult.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVE: The objective of our study was to determine the likelihood of malignancy in thyroid nodules and the risk of a nondiagnostic fine-needle aspiration biopsy (FNAB) on the basis of the demographic characteristics of the patients and sonographic features of the nodules.nnMATERIALS AND METHODS: Between January 2002 and November 2007, 2,338 ultrasound-guided thyroid, thyroid bed, and cervical lymph node FNABs were performed at a tertiary referral center. Entry criteria for our retrospective study were adult patients who underwent thyroid nodule FNAB and had previously undergone diagnostic sonography. From previous reports for 944 thyroid nodules (739 nodules in women and 205 nodules in men), four sonographic features were recorded: longest dimension, morphology, presence of microcalcifications, and presence of lymphadenopathy. The final diagnosis of each nodule was classified as benign, malignant, or nondiagnostic on the basis of surgical pathology when available and cytology otherwise and was analyzed for correlation with individual sonographic features and combinations of features.nnRESULTS: The prevalence of malignancy and of nondiagnostic FNAB in this study was 11.0% and 11.8%, respectively. Statistically significant (p < 0.05) findings in malignant nodules were younger patient age (< or = 45 years; odds ratio [OR], 1.54) and solid nodule morphology (OR, 2.38). The significant predictors of a nondiagnostic-quality FNAB were older patient age (> 75 years; OR, 1.95) and a nodule > or = 10 mm (OR, 1.45). Adding information about the other evaluated ultrasound features did not lead to a significant result.nnCONCLUSION: Malignant thyroid nodules tend to be solid (86.5%). Patients older than 75 years showed a clearly increased risk of nondiagnostic FNAB, but to predict a higher risk of malignancy or of nondiagnostic FNAB using ultrasound remains difficult.
2008
Ma, Xiaozhou; Samir, Anthony E; Holalkere, Nagaraj-Setty; Sahani, Dushyant V
Optimal arterial phase imaging for detection of hypervascular hepatocellular carcinoma determined by continuous image capture on 16-MDCT Journal Article
In: AJR Am J Roentgenol, vol. 191, no. 3, pp. 772–777, 2008, ISSN: 1546-3141.
@article{pmid18716108,
title = {Optimal arterial phase imaging for detection of hypervascular hepatocellular carcinoma determined by continuous image capture on 16-MDCT},
author = {Xiaozhou Ma and Anthony E Samir and Nagaraj-Setty Holalkere and Dushyant V Sahani},
doi = {10.2214/AJR.07.3452},
issn = {1546-3141},
year = {2008},
date = {2008-09-01},
journal = {AJR Am J Roentgenol},
volume = {191},
number = {3},
pages = {772--777},
abstract = {OBJECTIVE: The purpose of this study is to estimate the optimal time delay before the initiation of arterial phase scanning for detection of hypervascular hepatocellular carcinoma (HCC) on 16-MDCT when a rapid bolus injection of contrast medium is administered.nnSUBJECTS AND METHODS: In this prospective study, 25 patients (19 men and six women; mean age, 63.5 years; age range, 50-81 years) with pathologically confirmed HCC were included. Dynamic 16-MDCT imaging was performed in cine mode using 70 mL of nonionic iodinated contrast medium (300 mg I/mL) at an injection rate of 7 mL/s. Four consecutive 5-mm-thick slices at the maximum diameter of the HCC were selected as the region of interest. Time-attenuation curves were generated by region of interest drawn on the aorta, tumor, and liver. Qualitative assessments of conspicuity for contrast medium wash-in, peak, and wash-out of aorta and tumor were performed.nnRESULTS: There were 108 arterial phase enhancing lesions (mean [+/-SD], 4.9 +/- 2.4 cm; range, 0.7-12.9 cm) in the 25 patients. The maximum Hounsfield value of aorta, tumor, and background liver parenchyma were 463.8 +/- 98 HU, 106.5 +/- 19 HU, and 98.3 +/- 14 HU, respectively. At the time of onset of peak tumor enhancement, the difference between tumor density and background liver density was 38.2 +/- 19 HU. The time-attenuation curve showed that the mean times of contrast enhancement start, peak, and end were 9.2 +/- 2.7 seconds, 19.4 +/- 2.1 seconds, and 38 +/- 13.5 seconds, respectively, for the aorta, and 15.5 +/- 2.6 seconds, 26.3 +/- 2.9 seconds, and 57.7 +/- 14.4 seconds, respectively, for 25 pathologically confirmed hepatocellular carcinomas. Qualitatively, the mean times of contrast enhancement wash-in, peak, and washout were 10.2 +/- 2.8 seconds, 19.9 +/- 3 seconds, and 39.9 +/- 9.2 seconds, respectively for the aorta, and 18 +/- 4.2 seconds, 27 +/- 3 seconds, and 55.7 +/- 21 seconds, respectively, for tumor. There were no differences between quantitative and qualitative measurements of wash-in and peak time for the aorta (p = 0.00017, p = 0.00016) and tumor (p = 0.00163, p = 0.00040).nnCONCLUSION: When using 70 mL of 300 mg I/mL of contrast medium with an injection rate of 7 mL/s in 16-MDCT scanning, the optimal time to initiate scanning for HCC is 26.3 +/- 2.9 seconds (range, 24.0-34.5 seconds) after contrast medium administration.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVE: The purpose of this study is to estimate the optimal time delay before the initiation of arterial phase scanning for detection of hypervascular hepatocellular carcinoma (HCC) on 16-MDCT when a rapid bolus injection of contrast medium is administered.nnSUBJECTS AND METHODS: In this prospective study, 25 patients (19 men and six women; mean age, 63.5 years; age range, 50-81 years) with pathologically confirmed HCC were included. Dynamic 16-MDCT imaging was performed in cine mode using 70 mL of nonionic iodinated contrast medium (300 mg I/mL) at an injection rate of 7 mL/s. Four consecutive 5-mm-thick slices at the maximum diameter of the HCC were selected as the region of interest. Time-attenuation curves were generated by region of interest drawn on the aorta, tumor, and liver. Qualitative assessments of conspicuity for contrast medium wash-in, peak, and wash-out of aorta and tumor were performed.nnRESULTS: There were 108 arterial phase enhancing lesions (mean [+/-SD], 4.9 +/- 2.4 cm; range, 0.7-12.9 cm) in the 25 patients. The maximum Hounsfield value of aorta, tumor, and background liver parenchyma were 463.8 +/- 98 HU, 106.5 +/- 19 HU, and 98.3 +/- 14 HU, respectively. At the time of onset of peak tumor enhancement, the difference between tumor density and background liver density was 38.2 +/- 19 HU. The time-attenuation curve showed that the mean times of contrast enhancement start, peak, and end were 9.2 +/- 2.7 seconds, 19.4 +/- 2.1 seconds, and 38 +/- 13.5 seconds, respectively, for the aorta, and 15.5 +/- 2.6 seconds, 26.3 +/- 2.9 seconds, and 57.7 +/- 14.4 seconds, respectively, for 25 pathologically confirmed hepatocellular carcinomas. Qualitatively, the mean times of contrast enhancement wash-in, peak, and washout were 10.2 +/- 2.8 seconds, 19.9 +/- 3 seconds, and 39.9 +/- 9.2 seconds, respectively for the aorta, and 18 +/- 4.2 seconds, 27 +/- 3 seconds, and 55.7 +/- 21 seconds, respectively, for tumor. There were no differences between quantitative and qualitative measurements of wash-in and peak time for the aorta (p = 0.00017, p = 0.00016) and tumor (p = 0.00163, p = 0.00040).nnCONCLUSION: When using 70 mL of 300 mg I/mL of contrast medium with an injection rate of 7 mL/s in 16-MDCT scanning, the optimal time to initiate scanning for HCC is 26.3 +/- 2.9 seconds (range, 24.0-34.5 seconds) after contrast medium administration.
Steinman, Theodore I; Samir, Anthony E; Cornell, Lynn D
In: N Engl J Med, vol. 359, no. 9, pp. 951–960, 2008, ISSN: 1533-4406.
@article{pmid18753652,
title = {Case records of the Massachusetts General Hospital. Case 27-2008. A 64-year-old man with abdominal pain, nausea, and an elevated level of serum creatinine},
author = {Theodore I Steinman and Anthony E Samir and Lynn D Cornell},
doi = {10.1056/NEJMcpc0804600},
issn = {1533-4406},
year = {2008},
date = {2008-08-01},
journal = {N Engl J Med},
volume = {359},
number = {9},
pages = {951--960},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Miller, Janet C; Samir, Anthony; McGovern, Francis J; Thrall, James H; Lee, Susanna I
Evaluation of renal masses Journal Article
In: J Am Coll Radiol, vol. 5, no. 7, pp. 857–860, 2008, ISSN: 1558-349X.
@article{pmid18585667,
title = {Evaluation of renal masses},
author = {Janet C Miller and Anthony Samir and Francis J McGovern and James H Thrall and Susanna I Lee},
doi = {10.1016/j.jacr.2008.01.022},
issn = {1558-349X},
year = {2008},
date = {2008-07-01},
journal = {J Am Coll Radiol},
volume = {5},
number = {7},
pages = {857--860},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cantwell, Colin P; Wah, Tze M; Gervais, Debra A; Eisner, Brian H; Arellano, Ronald; Uppot, Raul N; Samir, Anthony E; Irving, Henry C; McGovern, Francis; Mueller, Peter R
In: J Vasc Interv Radiol, vol. 19, no. 7, pp. 1034–1040, 2008, ISSN: 1051-0443.
@article{pmid18589317,
title = {Protecting the ureter during radiofrequency ablation of renal cell cancer: a pilot study of retrograde pyeloperfusion with cooled dextrose 5% in water},
author = {Colin P Cantwell and Tze M Wah and Debra A Gervais and Brian H Eisner and Ronald Arellano and Raul N Uppot and Anthony E Samir and Henry C Irving and Francis McGovern and Peter R Mueller},
doi = {10.1016/j.jvir.2008.04.005},
issn = {1051-0443},
year = {2008},
date = {2008-07-01},
journal = {J Vasc Interv Radiol},
volume = {19},
number = {7},
pages = {1034--1040},
abstract = {PURPOSE: To describe early experience with cooled dextrose 5% in water (D5W) solution retrograde pyeloperfusion during radiofrequency (RF) ablation of renal cell carcinoma (RCC) within 1.5 cm of the ureter with respect to feasibility, safety, and incidence of residual/recurrent tumor in proximity to the cooled collecting system.nnMATERIALS AND METHODS: Between November 2004 and April 2007, 17 patients underwent 19 RF ablation sessions of RCCs within 1.5 cm of the ureter during cooled D5W pyeloperfusion (nine men, eight women; mean tumor size, 3.5 cm; mean age, 73 y; mean distance to ureter, 7 mm). RF ablation was performed with pulsed impedance control current. The records and imaging studies of patients treated with this technique were reviewed for demographics, indication, technique, complications, and tumor recurrence.nnRESULTS: All 19 RF ablation and ureteral catheter placement procedures were technically successful. No patient developed a ureteral stricture or hydronephrosis during a mean of 14 months of follow-up (range, 4-32 months). Three patients had residual tumor on the first follow-up imaging study, but all three tumors were completely ablated after a second RF ablation session. No complications or deaths occurred. No recurrent tumor was seen anywhere in the treated tumors, and there was complete ablation of the tumor margin in proximity to the collecting system.nnCONCLUSIONS: RF ablation of RCC within 1.5 cm of the ureter is feasible with cooled D5W retrograde pyeloperfusion and is not associated with reduced efficacy, ureteral injury, or early recurrence.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: To describe early experience with cooled dextrose 5% in water (D5W) solution retrograde pyeloperfusion during radiofrequency (RF) ablation of renal cell carcinoma (RCC) within 1.5 cm of the ureter with respect to feasibility, safety, and incidence of residual/recurrent tumor in proximity to the cooled collecting system.nnMATERIALS AND METHODS: Between November 2004 and April 2007, 17 patients underwent 19 RF ablation sessions of RCCs within 1.5 cm of the ureter during cooled D5W pyeloperfusion (nine men, eight women; mean tumor size, 3.5 cm; mean age, 73 y; mean distance to ureter, 7 mm). RF ablation was performed with pulsed impedance control current. The records and imaging studies of patients treated with this technique were reviewed for demographics, indication, technique, complications, and tumor recurrence.nnRESULTS: All 19 RF ablation and ureteral catheter placement procedures were technically successful. No patient developed a ureteral stricture or hydronephrosis during a mean of 14 months of follow-up (range, 4-32 months). Three patients had residual tumor on the first follow-up imaging study, but all three tumors were completely ablated after a second RF ablation session. No complications or deaths occurred. No recurrent tumor was seen anywhere in the treated tumors, and there was complete ablation of the tumor margin in proximity to the collecting system.nnCONCLUSIONS: RF ablation of RCC within 1.5 cm of the ureter is feasible with cooled D5W retrograde pyeloperfusion and is not associated with reduced efficacy, ureteral injury, or early recurrence.
Catalano, Onofrio A; Samir, Anthony E; Sahani, Dushyant V; Hahn, Peter F
Pixel distribution analysis: can it be used to distinguish clear cell carcinomas from angiomyolipomas with minimal fat? Journal Article
In: Radiology, vol. 247, no. 3, pp. 738–746, 2008, ISSN: 1527-1315.
@article{pmid18413886,
title = {Pixel distribution analysis: can it be used to distinguish clear cell carcinomas from angiomyolipomas with minimal fat?},
author = {Onofrio A Catalano and Anthony E Samir and Dushyant V Sahani and Peter F Hahn},
doi = {10.1148/radiol.2473070785},
issn = {1527-1315},
year = {2008},
date = {2008-06-01},
journal = {Radiology},
volume = {247},
number = {3},
pages = {738--746},
abstract = {PURPOSE: To retrospectively determine if pixel histogram analysis of unenhanced computed tomographic (CT) images can be used to distinguish angiomyolipomas (AMLs) with minimal fat from clear cell renal cell carcinomas (CCRCCs).nnMATERIALS AND METHODS: The human studies committee approved this HIPAA-complaint study, with waiver of informed consent. Patients with pathologically proved AMLs lacking visible macroscopic fat at CT and patients with pathologically proved CCRCCs were included. Lesions were measured, and a histogram (number of pixels with each attenuation) was calculated electronically within a central region of interest. The percentage of pixels below the attenuation thresholds -20 HU and 10 HU was calculated in both cohorts. The unpaired Student t test was used to compare the average percentage of subthreshold pixels at each threshold. P < .05 indicated a significant difference. The number of lesions with more than the selected percentage of subthreshold pixels was calculated in both groups, and the chi(2) test was used to test the significance of differences between cohorts. The area under the receiver operating characteristic (ROC) curve was used to determine if any percentage of subthreshold pixels could be used to differentiate between the two cohorts.nnRESULTS: There were 22 patients with pathologically proved AMLs lacking visible macroscopic fat on CT images. Tuberous sclerosis affected three of these patients. Mean maximal transverse lesion diameter was 20 mm (range, 11-38 mm). There were 28 patients in the CCRCC comparison group. Mean maximal transverse lesion diameter was 26 mm (range, 15-36 mm). Neither the Student t test (P > .2 for all thresholds <0 HU) nor the chi(2) test (P > .15 for all thresholds <0 HU) revealed a significant difference between cohorts. A lesion with more low-attenuation pixels was significantly more likely to be characterized as CCRCC than as AML with ROC curve analysis.nnCONCLUSION: Once AMLs with visible fat on CT images are excluded, pixel histogram analysis cannot be used to distinguish between AMLs and CCRCCs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: To retrospectively determine if pixel histogram analysis of unenhanced computed tomographic (CT) images can be used to distinguish angiomyolipomas (AMLs) with minimal fat from clear cell renal cell carcinomas (CCRCCs).nnMATERIALS AND METHODS: The human studies committee approved this HIPAA-complaint study, with waiver of informed consent. Patients with pathologically proved AMLs lacking visible macroscopic fat at CT and patients with pathologically proved CCRCCs were included. Lesions were measured, and a histogram (number of pixels with each attenuation) was calculated electronically within a central region of interest. The percentage of pixels below the attenuation thresholds -20 HU and 10 HU was calculated in both cohorts. The unpaired Student t test was used to compare the average percentage of subthreshold pixels at each threshold. P < .05 indicated a significant difference. The number of lesions with more than the selected percentage of subthreshold pixels was calculated in both groups, and the chi(2) test was used to test the significance of differences between cohorts. The area under the receiver operating characteristic (ROC) curve was used to determine if any percentage of subthreshold pixels could be used to differentiate between the two cohorts.nnRESULTS: There were 22 patients with pathologically proved AMLs lacking visible macroscopic fat on CT images. Tuberous sclerosis affected three of these patients. Mean maximal transverse lesion diameter was 20 mm (range, 11-38 mm). There were 28 patients in the CCRCC comparison group. Mean maximal transverse lesion diameter was 26 mm (range, 15-36 mm). Neither the Student t test (P > .2 for all thresholds <0 HU) nor the chi(2) test (P > .15 for all thresholds <0 HU) revealed a significant difference between cohorts. A lesion with more low-attenuation pixels was significantly more likely to be characterized as CCRCC than as AML with ROC curve analysis.nnCONCLUSION: Once AMLs with visible fat on CT images are excluded, pixel histogram analysis cannot be used to distinguish between AMLs and CCRCCs.
2006
Hunter, Scott; Samir, Anthony; Eisner, Brian; Gervais, Debra; Maher, Michael; Hahn, Peter; McGovern, Francis; Mueller, Peter
Diagnosis of renal lymphoma by percutaneous image guided biopsy: experience with 11 cases Journal Article
In: J Urol, vol. 176, no. 5, pp. 1952–6; discussion 1956, 2006, ISSN: 0022-5347.
@article{pmid17070216,
title = {Diagnosis of renal lymphoma by percutaneous image guided biopsy: experience with 11 cases},
author = {Scott Hunter and Anthony Samir and Brian Eisner and Debra Gervais and Michael Maher and Peter Hahn and Francis McGovern and Peter Mueller},
doi = {10.1016/j.juro.2006.07.032},
issn = {0022-5347},
year = {2006},
date = {2006-11-01},
journal = {J Urol},
volume = {176},
number = {5},
pages = {1952--6; discussion 1956},
abstract = {PURPOSE: We reviewed an institutional experience with image guided percutaneous biopsy of focal renal masses that yielded a diagnosis of lymphoma.nnMATERIALS AND METHODS: We retrospectively reviewed the hospital records of patients undergoing percutaneous renal biopsy between September 1997 and February 2005.nnRESULTS: A total of 407 image guided focal renal lesion biopsies were identified. A diagnosis of lymphoma was made in 11 patients (3%). Biopsies were performed under computerized tomography guidance in 9 cases (82%) and under ultrasound guidance in 2 (18%). Core biopsies were performed in 11 cases, while fine needle aspiration was done in 10 (91%). Fine needle aspirations underwent cytological analysis in 10 cases and flow cytometry analysis in 9. The final combined pathological diagnoses were B-cell lymphoma in 10 cases and lymphomatoid granulomatosis in 1. Analysis of core biopsies yielded a diagnosis of B-cell lymphoma in 10 cases (91%) and lymphomatoid granulomatosis in 1. Analysis of fine needle aspirations yielded a diagnosis of B-cell lymphoma in 3 cases (30%), lymphoma in 4 (40%), suspicion of lymphoma in 1 (10%), atypical cells in 1 (10%) and a nondiagnostic sample in 1 (10%). Flow cytometry concurred with cytology in the diagnosis of B-cell lymphoma in 2 cases, allowed the identification of lymphoma subtype, which was not made on cytology, in 4, was insufficient in 2 and identified no abnormality in 1. No patients underwent surgery or an ablative procedure.nnCONCLUSIONS: Core biopsy has a higher diagnostic yield than fine needle aspiration for diagnosing renal lymphoma. Flow cytometry analysis adds additional diagnostic information to cytological examination of fine needle aspiration samples. Accurate diagnosis of lymphoma in these cases allowed proper treatment without unnecessary surgery or other procedures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: We reviewed an institutional experience with image guided percutaneous biopsy of focal renal masses that yielded a diagnosis of lymphoma.nnMATERIALS AND METHODS: We retrospectively reviewed the hospital records of patients undergoing percutaneous renal biopsy between September 1997 and February 2005.nnRESULTS: A total of 407 image guided focal renal lesion biopsies were identified. A diagnosis of lymphoma was made in 11 patients (3%). Biopsies were performed under computerized tomography guidance in 9 cases (82%) and under ultrasound guidance in 2 (18%). Core biopsies were performed in 11 cases, while fine needle aspiration was done in 10 (91%). Fine needle aspirations underwent cytological analysis in 10 cases and flow cytometry analysis in 9. The final combined pathological diagnoses were B-cell lymphoma in 10 cases and lymphomatoid granulomatosis in 1. Analysis of core biopsies yielded a diagnosis of B-cell lymphoma in 10 cases (91%) and lymphomatoid granulomatosis in 1. Analysis of fine needle aspirations yielded a diagnosis of B-cell lymphoma in 3 cases (30%), lymphoma in 4 (40%), suspicion of lymphoma in 1 (10%), atypical cells in 1 (10%) and a nondiagnostic sample in 1 (10%). Flow cytometry concurred with cytology in the diagnosis of B-cell lymphoma in 2 cases, allowed the identification of lymphoma subtype, which was not made on cytology, in 4, was insufficient in 2 and identified no abnormality in 1. No patients underwent surgery or an ablative procedure.nnCONCLUSIONS: Core biopsy has a higher diagnostic yield than fine needle aspiration for diagnosing renal lymphoma. Flow cytometry analysis adds additional diagnostic information to cytological examination of fine needle aspiration samples. Accurate diagnosis of lymphoma in these cases allowed proper treatment without unnecessary surgery or other procedures.