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Featured researches published by Anthony E. Samir.


Journal of Vascular and Interventional Radiology | 2008

Protecting the Ureter during Radiofrequency Ablation of Renal Cell Cancer: A Pilot Study of Retrograde Pyeloperfusion with Cooled Dextrose 5% in Water

Colin P. Cantwell; Tze M. Wah; Debra A. Gervais; Brian H. Eisner; Ronald S. Arellano; Raul N. Uppot; Anthony E. Samir; Henry C. Irving; Francis J. McGovern; Peter R. Mueller

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. MATERIALS 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. RESULTS 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. CONCLUSIONS 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.


Thyroid | 2012

Ultrasound-Guided Percutaneous Thyroid Nodule Core Biopsy: Clinical Utility in Patients with Prior Nondiagnostic Fine-Needle Aspirate

Anthony E. Samir; Abhinav Vij; Melanie K. Seale; Gaurav S. Desai; Elkan F. Halpern; William C. Faquin; Sareh Parangi; Peter F. Hahn; Gilbert H. Daniels

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. METHODS 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. RESULTS 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. CONCLUSION 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.


Radiology | 2015

Shear-Wave Elastography for the Estimation of Liver Fibrosis in Chronic Liver Disease: Determining Accuracy and Ideal Site for Measurement

Anthony E. Samir; Manish Dhyani; Abhinav Vij; Atul K. Bhan; Elkan F. Halpern; Jorge Méndez-Navarro; Kathleen E. Corey; Raymond T. Chung

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. MATERIALS 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. RESULTS 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. CONCLUSION 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.


Radiology | 2008

Pixel Distribution Analysis : Can It be Used to Distinguish Clear Cell Carcinomas from Angiomyolipomas with Minimal Fat?

O. Catalano; Anthony E. Samir; Dushyant V. Sahani; Peter F. Hahn

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). MATERIALS 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. RESULTS 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. CONCLUSION Once AMLs with visible fat on CT images are excluded, pixel histogram analysis cannot be used to distinguish between AMLs and CCRCCs.


American Journal of Roentgenology | 2009

Fine-Needle Aspiration Biopsy of Thyroid Nodules: Experience in a Cohort of 944 Patients

Nina D. Baier; Peter F. Hahn; Debra A. Gervais; Anthony E. Samir; Elkan F. Halpern; Peter R. Mueller; Mukesh G. Harisinghani

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. MATERIALS 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. RESULTS 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. CONCLUSION 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.


internaltional ultrasonics symposium | 2013

RSNA/QIBA: Shear wave speed as a biomarker for liver fibrosis staging

Timothy J. Hall; Andy Milkowski; Brian S. Garra; Paul L. Carson; Mark L. Palmeri; Kathy Nightingale; Ted Lynch; Abdullah Alturki; Michael P. Andre; Stephane Audiere; Jeffery Bamber; Richard G. Barr; Jeremy Bercoff; Jessica Bercoff; Miguel Bernal; Javier Brum; Huan Wee Chan; Shigao Chen; Claude Cohen-Bacrie; Mathieu Couade; Allison Daniels; Ryan J. DeWall; Jonathan R. Dillman; Richard L. Ehman; S. F. Franchi-Abella; Jérémie Fromageau; Jean-Luc Gennisson; Jean Pierre Henry; Nikolas M. Ivancevich; Jan Kalin

An interlaboratory study of shear wave speed (SWS) estimation was performed. Commercial shear wave elastography systems from Fibroscan, Philips, Siemens and Supersonic Imagine, as well as several custom laboratory systems, were involved. Fifteen sites were included in the study. CIRS manufactured and donated 11 pairs of custom phantoms designed for the purposes of this investigation. Dynamic mechanical tests of equivalent phantom materials were also performed. The results of this study demonstrate that there is very good agreement among SWS estimation systems, but there are several sources of bias and variance that can be addressed to improve consistency of measurement results.


Thyroid | 2012

Diagnostic Yield of Nondiagnostic Thyroid Nodules Is Not Altered by Timing of Repeat Biopsy

Carrie C. Lubitz; Sushruta S. Nagarkatti; William C. Faquin; Anthony E. Samir; Maria Hassan; Giuseppe Barbesino; Douglas S. Ross; Gregory W. Randolph; Randall D. Gaz; Antonia E. Stephen; Richard A. Hodin; Gilbert H. Daniels; Sareh Parangi

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. METHODS 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 Hashimotos 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. RESULTS 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). CONCLUSION The timing of repeat FNAB for an initial ND FNAB does not affect diagnostic yield of the repeat FNAB.


Journal of The American College of Radiology | 2011

Decision Support for Radiologist Report Recommendations

Giles W. Boland; James H. Thrall; G. Scott Gazelle; Anthony E. Samir; Daniel I. Rosenthal; Tarik K. Alkasab

THE CLINICAL PROBLEM The past 2 decades have seen a remarkable increase in the capabilities, utilization, and cost burden of medical imaging [1-6]. This increase in demand for diagnostic imaging has put imaging in the spotlight as a target for cuts in reimbursement [1-7]. Much of the growth in imaging utilization is clearly beneficial to medical practice and increased quality of care [8]. However, we are also facing a challenge from some referring physicians who regard recommendations for additional imaging made by radiologists in their official reports as a form of “self-referral” [9]. Also, some physicians challenge radiologist recommendations on the grounds that they feel that such recommendations increase their risk for medical liability if they go unheeded [10]. Specialists often feel they know better than radiologists about what to do next and resent being pressured to act through the recommendation process. To promote the optimal use of imaging, the ACR established a program in 1992 to develop the ACR Appropriateness Criteria [11]. These riteria are designed to help referring hysicians select the right imaging xaminations for their patients: the roverbial goal of right patient, right est, right reason, and right protocol. e now argue here that a similar set f appropriateness criteria should be eveloped to guide radiologists as hey make recommendations for aditional imaging. They should be obective, evidence based, and consenus driven—including input from onradiologists—just as the original CR Appropriateness Criteria are. hey need to be presented to radiol-


American Journal of Roentgenology | 2008

Optimal Arterial Phase Imaging for Detection of Hypervascular Hepatocellular Carcinoma Determined by Continuous Image Capture on 16-MDCT

Xiaozhou Ma; Anthony E. Samir; Nagaraj-Setty Holalkere; Dushyant V. Sahani

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. SUBJECTS 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. RESULTS 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). CONCLUSION 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.


Journal of The American Society of Echocardiography | 2015

Contrast-Enhanced Ultrasound: A Novel Noninvasive, Nonionizing Method for the Detection of Brown Adipose Tissue in Humans

Aidan Flynn; Qian Li; Marcello Panagia; Amr Abdelbaky; Megan H. MacNabb; Anthony E. Samir; Aaron M. Cypess; Arthur E. Weyman; Ahmed Tawakol; Marielle Scherrer-Crosbie

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. METHODS 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. RESULTS 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). CONCLUSIONS 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.

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Brian W. Anthony

Massachusetts Institute of Technology

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