Ethan J Halpern

Thomas Jefferson University, Philadelphia, Pennsylvania, United States

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Publications (208)593.32 Total impact

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    ABSTRACT: To evaluate knowledge-based iterative model reconstruction (IMR) to improve image quality and reduce radiation dose in coronary computed tomography angiography (cCTA). We evaluated 45 consecutive cCTA studies, including 25 studies performed with an 80% systolic dose reduction using tube current modulation (TCM). Each study was reconstructed with filtered back projection (FBP), hybrid iterative reconstruction (iDose(4)), and IMR in a diastolic phase. Additional systolic phase reconstructions were obtained for TCM studies. Mean pixel attenuation value and standard deviation (SD) were measured in the left ventricle and left main coronary artery. Subjective scores were obtained by two independent reviewers on a 5-point scale for definitions of contours of small coronary arteries (<3 mm), coronary calcifications, noncalcified plaque, and overall diagnostic confidence for the presence/absence of stenosis. There was no significant difference in pixel intensity among FBP, iDose(4), and IMR (P > .8). For diastolic phase images, noise amplitude in the left main coronary artery was reduced by a factor of 1.3 from FBP to iDose(4) (SD = 99 vs. 74; P = .005) and by a factor of 2.6 from iDose(4) to IMR (SD = 74 vs. 28; P < .001). For systolic phase TCM images, noise amplitude in the left main coronary artery was reduced by a factor of 2.3 from FBP to iDose(4) (SD = 322 vs. 142; P < .001) and by a factor of 3.0 from iDose(4) to IMR (SD = 142 vs. 48; P < .001). All four subjective image quality scores were significantly better with IMR compared to iDose(4) and FBP (P < .001). The reduction in image noise amplitude and improvement in image quality scores were greatest among obese patients. IMR reduces intravascular noise on cCTA by 86%-88% compared to FBP, and improves image quality at radiation exposure levels 80% below our standard technique.
    Academic radiology 06/2014; 21(6):805-11. · 2.09 Impact Factor
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    ABSTRACT: A news article in June 2011 reported that Medicare claims showed considerable overuse of "double" CT scans of the thorax (ie, combined scans without contrast followed by with contrast) at a number of hospitals. Most radiologists agree that they should be done only on rare occasions. The aim of this study was to determine what proportion of all thoracic CT scans are combined scans in the Medicare population. The data sources were the Medicare Part B Physician/Supplier Procedure Summary Master Files for 2001 to 2011. The 3 Current Procedural Terminology codes for thoracic CT (with contrast, without contrast, and without plus with contrast) were selected. Utilization rates per 1,000 beneficiaries and the percentage that were combined scans were calculated. The utilization rate of combined scans increased from 2001 through 2006, remained steady in 2007, but then decreased sharply thereafter. The compound annual rate of change from 2007 to 2011 was -10.4%. From 2001 through 2006, combined thoracic CT scans constituted 6.0% to 6.1% of all thoracic CT scans. However, from 2006 to 2011, this percentage progressively declined, reaching a low of 4.2% in 2011. Despite the 2011 news report, only a very small percentage of thoracic CT scans nationwide are done both without and with contrast. Moreover, that percentage dropped by almost one-third from 2006 to 2011, suggesting that the practice is declining. The figure of 4.2% can be used as a benchmark against which to judge radiology facilities in the future.
    Journal of the American College of Radiology: JACR 04/2014;
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    ABSTRACT: Purpose To compare the elasticity of the median nerve (MN) between healthy volunteers and patients with carpal tunnel syndrome (CTS) and to evaluate the diagnostic utility of sonoelastographic measurements of the elasticity of the MN. Materials and Methods This study was performed with institutional review board approval and written informed consent from all participants. Hands in 22 healthy volunteers and in 31 patients with symptomatic CTS were studied. The cross-sectional area (CSA) and the elasticity of the MN, which was measured as the acoustic coupler (AC)/MN strain ratio, were evaluated. Results Both hands in 22 healthy volunteers (three men [mean age, 52.7 years; age range, 41-65 years]; 19 women [mean age, 62.2 years; age range, 40-88 years]) and 43 hands in 31 patients with symptomatic CTS (three men [mean age, 69.0 years; age range, 46-88 years]; 28 women [mean age, 61.2 years; age range, 39-92 years]) were studied. Both the AC/MN strain ratio and the CSA in the patients with CTS were significantly higher than those in the healthy volunteers (P < .001). The presence of CTS was predicted by means of AC/MN strain ratio and CSA cutoff values, respectively, of 4.3 and 11 mm(2), with areas under the receiver operating characteristic curves (AUCs) of 0.78 (95% confidence interval [CI]: 0.69, 0.88) and 0.85 (95% CI: 0.78, 0.93). A logistic model that combined the AC/MN strain ratio and the CSA improved diagnostic accuracy for CTS, with an AUC of 0.91 (95% CI: 0.85, 0.97; P < .001). Conclusion Sonoelastography provides significant improvement in the diagnostic accuracy of the ultrasonographic assessment of CTS. © RSNA, 2013.
    Radiology 02/2014; 270(2):481-6. · 6.34 Impact Factor
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    ABSTRACT: Purpose A news article in June 2011 reported that Medicare claims showed considerable overuse of “double” CT scans of the thorax (ie, combined scans without contrast followed by with contrast) at a number of hospitals. Most radiologists agree that they should be done only on rare occasions. The aim of this study was to determine what proportion of all thoracic CT scans are combined scans in the Medicare population. Methods The data sources were the Medicare Part B Physician/Supplier Procedure Summary Master Files for 2001 to 2011. The 3 Current Procedural Terminology codes for thoracic CT (with contrast, without contrast, and without plus with contrast) were selected. Utilization rates per 1,000 beneficiaries and the percentage that were combined scans were calculated. Results The utilization rate of combined scans increased from 2001 through 2006, remained steady in 2007, but then decreased sharply thereafter. The compound annual rate of change from 2007 to 2011 was −10.4%. From 2001 through 2006, combined thoracic CT scans constituted 6.0% to 6.1% of all thoracic CT scans. However, from 2006 to 2011, this percentage progressively declined, reaching a low of 4.2% in 2011. Conclusions Despite the 2011 news report, only a very small percentage of thoracic CT scans nationwide are done both without and with contrast. Moreover, that percentage dropped by almost one-third from 2006 to 2011, suggesting that the practice is declining. The figure of 4.2% can be used as a benchmark against which to judge radiology facilities in the future.
    Journal of the American College of Radiology. 01/2014;
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    ABSTRACT: In 2009, the add-on codes for spectral Doppler and color flow Doppler echocardiography were bundled into the code for primary transthoracic echocardiography. The relative value units for the new single code were substantially lower than the previous sum for the 3 codes. The purpose of this study was to see how this affected the distribution of outpatient echocardiographic studies between cardiology offices and hospital outpatient departments (HOPDs). The 2005 to 2011 Medicare databases were used. All echocardiography Current Procedural Terminology codes were selected. Specialty codes identified those done by cardiologists (who do most echocardiographic studies). Place-of-service codes identified those done in offices and HOPDs. Procedure volumes and utilization rates per 1,000 were determined each year before and after bundling occurred in 2009. Cardiologists' office echocardiography utilization rate rose from 219.5 per 1,000 in 2005 to 257.1 in 2008 (+17%), then dropped to 100.0 in 2009 (-61%) because of bundling. Their HOPD echocardiography rate rose from 72.2 in 2005 to 76.5 in 2008 (+6%), then dropped to 35.0 in 2009 (-54%). From 2009 to 2011, cardiologists' office echocardiography rate dropped again from 100.0 to 88.8 (-11%), while their HOPD rate increased from 35.0 to 46.1 (+32%). Echocardiography code bundling produced the expected sharp drop in outpatient claims from cardiologists in 2009. But after bundling, office echocardiography rates continued to drop, while HOPD rates increased. It seems that in this instance, code bundling led to the closure of many cardiology offices and a resultant shift of echocardiography from that lower cost setting to the higher cost HOPD setting.
    Journal of the American College of Radiology: JACR 12/2013;
  • Jacob P. Deutsch, Ethan J. Halpern
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    ABSTRACT: PURPOSE To compare myocardial perfusion data obtained during coronary CT angiography (cCTA) with stress nuclear imaging. METHOD AND MATERIALS We retrospectively identified 53 patients with ECG-gated cCTA and stress nuclear perfusion imaging performed within 30 days. Among these patients, 37 had helical cCTA with both diastolic and systolic imaging; 16 had only diastolic imaging. cCTA was performed with the iCT 256 slice scanner (Philips Medical Systems), and myocardial perfusion was evaluated with the comprehensive cardiac analysis application (Philips Intellispace Portal version 5.0). Areas of perfusion abnormality were identified by subjective evaluation of a binary polar map based upon the American Heart Association standardized 16 myocardial segment model. cCTA perfusion abnormalities were also identified automatically by quantitative analysis of a defect probability map using a cutoff probability of 15%. RESULTS Fifteen of 53 patients demonstrated perfusion defects on nuclear imaging, including 11 fixed defects and 15 reversible defects. There was complete agreement between the subjective assessment of cCTA polar maps and the automated quantitative cCTA analysis on location of defects, although the size of one defect was larger by subjective assessment while two defects were judged to be larger by quantitative assessment. Eleven of these 15 patients had cCTA imaging in both systole and diastole. In a by-patient analysis, true positive perfusion defects were identified on cCTA in 10/15 (67%) by diastolic imaging and in 9/11(82%) by systolic imaging (p=0.17). False positive perfusion defects were identified in 37/53 (70%) of patients by diastolic cCTA imaging and in 36/37 (97%) of patients by systolic cCTA imaging. Furthermore, among true positive cases, cCTA overestimated defect size in 10/10 (100%) of cases. CONCLUSION Systolic phase cCTA imaging of the myocardium may be more sensitive for detection of perfusion defects as compared to diastolic phase imaging. Although the majority of myocardial perfusion defects found by nuclear imaging are detected on cCTA with the comprehensive cardiac analysis application, this technique is unlikely to be clinically useful, given the high rate of false positive perfusion cCTA defects. CLINICAL RELEVANCE/APPLICATION A majority of myocardial perfusion can be identified by cCTA, but many of the apparent myocardial defects found during cCTA do not correspond with perfusion defects on nuclear imaging.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
  • Ethan J. Halpern
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    ABSTRACT: PURPOSE Percutaneous therapies for closure of atrial septal defects (ASD’s), patent foramen ovales (PFO’s) and ventricular septal defects (VSD's) require careful pre-operative planning. Although transesophageal echocardiography is routinely used, ECG-gated cardiac CT can provide additional 3D detail. We review our experience with ECG-gated CT of intracardiac septal defects prior to attempted repair, with echocardiographic and surgical correlation. METHOD AND MATERIALS A retrospective review of ECG-gated cardiac CT studies identified studies performed for pre-operative evaluation of ASD, PFO and VSD defects. Ten cases of ASD, 5 cases of PFO and 2 cases of VSD were identified. Each defect was evaluated in multiple projections using a CT workstation. CT results were compared to transthoracic/transesophageal echocardiography and with subsequent operative findings/decisions to determine whether CT imaging was helpful in these cases. RESULTS Septal defects were identified in all cases by the presence of shunting of contrast between the more densely opacified left heart and less densely opacified right heart. Definite enlargement of the right heart was identified in 7 patients. CT measurements of ASD size correlated well with echocardiography and operative reports. CT was most useful for measuring the tissue rim around an ASD to determine whether a sufficient rim was present for percutaneous closure. In three patients CT identified findings that were not suggested by transesophageal echocardiography and that changed the operative approach: one patient with an additional septal defect (2 ASD’s), one patient with an absent tissue rim along the antero-superior aspect of an ASD adjacent to the aortic root, and one patient with tricuspid chordal structures along a VSD. CT clearly defined the length of the interatrial tunnel in patients with PFO’s. In one patient with a PFO, the CT demonstrated a right to left shunt. CONCLUSION Defects in the atrial or ventricular septum are clearly defined by ECG-gated cardiac CT, and the defect location is defined relative to adjacent structures (SVC, IVC, aortic root, chordal structures). The size of the defect and its associated tissue rim are easily quantified by 3-dimensional analysis of CT data. The presence and direction of intracardiac shunts may also be demonstrated. CLINICAL RELEVANCE/APPLICATION Cardiac CTA is a useful adjunct to echocardiography in the pre-operative assessment of intracardiac septal defects.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: PURPOSE To evaluate the predictive value of cardiac risk factors and risk scores for coronary artery disease (CAD) and adverse outcomes in an emergency department (ED) population judged to be at low to intermediate risk for acute coronary syndrome (ACS). METHOD AND MATERIALS IRB approval was obtained for this HIPPA compliant, prospective cohort study. The study cohort included consecutive patients who presented to the ED with chest pain over a 36 month period, were admitted to the observation unit, evaluated with coronary CTA (cCTA) and agreed to provide written informed consent. Cardiac risk factors, clinical presentation, ECG and laboratory studies were recorded with a standard template; TIMI and GRACE scores were tabulated. cCTA findings were reviewed by two experienced cardiac radiologists, rated on a 6 level plaque burden scale, and classified for presence/absence of significant CAD (stenosis ≥ 50%). Adverse cardiovascular outcomes were recorded after 30 days. RESULTS Among 250 patients evaluated by cCTA, 143 (57%) had no CAD, 64 (26%) demonstrated minimal plaque (<30% stenosis), 26 (10%) demonstrated mild plaque (<50% stenosis), 9 (4%) demonstrated moderate single vessel disease (50-70% stenosis), 2 (1%) demonstrated moderate multivessel disease and 6 (2%) demonstrated severe disease (>70% stenosis). Six patients developed adverse cardiovascular outcomes. Among traditional cardiac risk factors, only age (older) and sex (male) were significant independent predictors of CAD. Correlation with CAD was poor for TIMI (r=0.12) and GRACE (r=0.09-0.23) risk scores. Although risk factors, patient presentation, and risk scores were poor predictors of CAD and adverse outcomes, cCTA identified severe CAD in all subjects with adverse outcomes. CONCLUSION Among patients who present to the ED with chest pain and are judged to be at low to intermediate risk of ACS, traditional risk factors, TIMI and GRACE scores are not useful to stratify patient risk for CAD and adverse outcomes. cCTA is an excellent predictor of outcome. CLINICAL RELEVANCE/APPLICATION Coronary CTA is superior to traditional risk factors for triage of patients presenting to the ED with chest pain and who are judged to be at low to intermediate risk of acute coronary syndrome.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
  • Hugh D White, Ethan J Halpern, Michael P Savage
    JACC. Cardiovascular imaging 12/2013; 6(12):1342-1345. · 14.29 Impact Factor
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    ABSTRACT: The objective of the study is to evaluate cardiac risk factors and risk scores for prediction of coronary artery disease (CAD) and adverse outcomes in an emergency department (ED) population judged to be at low to intermediate risk for acute coronary syndrome. Informed consent was obtained from consecutive ED patients who presented with chest pain and were evaluated with coronary computed tomography angiography (cCTA). Cardiac risk factors, clinical presentation, electrocardiogram, and laboratory studies were recorded; the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) scores were tabulated. Coronary computed tomography angiography findings were rated on a 6-level plaque burden scale and classified for significant CAD (stenosis ≥50%). Adverse cardiovascular outcomes were recorded at 30 days. Among 250 patients evaluated by cCTA, 143 (57%) had no CAD, 64 (26%) demonstrated minimal plaque (<30% stenosis), 26 (10%) demonstrated mild plaque (<50% stenosis), 9 (4%) demonstrated moderate single vessel disease (50%-70% stenosis), 2 (1%) demonstrated moderate multivessel disease, and 6 (2%) demonstrated severe disease (>70% stenosis). Six patients developed adverse cardiovascular outcomes. Among traditional cardiac risk factors, only age (older) and sex (male) were significant independent predictors of CAD. Correlation with CAD was poor for the TIMI (r = 0.12) and GRACE (r = 0.09-0.23) scores. The TIMI and GRACE scores were not useful to predict adverse outcomes. Coronary computed tomography angiography identified severe CAD in all subjects with adverse outcomes. Among ED patients who present with chest pain judged to be at low to intermediate risk for acute coronary syndrome, traditional risk factors are not useful to stratify risk for CAD and adverse outcomes. Coronary computed tomography angiography is an excellent predictor of CAD and outcome.
    The American journal of emergency medicine 09/2013; · 1.54 Impact Factor
  • Ethan J. Halpern
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    ABSTRACT: PURPOSE To explore the impact of training in medical professionalism on the perspective of radiology residents and medical students who are interested in radiology. METHOD AND MATERIALS Medical professionalism is included in the curriculum for our medical students, with required reading of the physician charter (Ann Intern Med 2002;136(3):243-6). At the conclusion of the program on medical professionalism attended by 3rd year medical students, informal group discussions were held with students interested in radiology about professionalism as it relates to radiology, based upon two articles in the radiology literature (Radiology 2010 257:22-23 & Radiology 2006 238:773-779). A similar journal club session was held with radiology residents after required reading of the physician charter. Students and residents were surveyed to describe their understanding of professionalism both before and after the group discussions. RESULTS Prior to the informal group discussion and journal club students and residents described professionalism in general terms as the obligation to treat others respectfully, and to treat patients as they themselves would hope to be treated. There was little awareness of the tensions between the principles of medical professionalism as espoused in the physician charter and the pressures to increase RVU productivity related to PACS and financial considerations. Specifically, students and residents did not appreciate the conflict between the principles of patient welfare and autonomy in the physician charter, and the decline in personal communication with patients and referring physicians in a PACS based practice. Students and residents uniformly expressed a better understanding of the conflict between professionalism and the pressures of a modern radiology practice, and a better appreciation for the importance of the physician charter after these sessions. CONCLUSION Although the principles of medical professionalism espoused in the physician charter have been adopted by the RSNA Professionalism Committee (Radiology 2006 238:383-386), trainees do not appreciate the implications of the charter to the practice of radiology. Small group discussions provide increased awareness of the importance of professionalism in an era of PACS based practice and increased pressure for RVU productivity. CLINICAL RELEVANCE/APPLICATION Small group discussions increase awareness on the implications of medical professionalism to the practice of radiology.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
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    ABSTRACT: PURPOSE To investigate the diagnostic accuracy of contrast enhanced transrectal ultrasound (CE-TRUS) in comparison with whole-mount radical prostatectomy specimens for the detection of prostate cancer. METHOD AND MATERIALS A retrospective review identified 58 subjects with CE-TRUS studies who subsequently underwent radical prostatectomy with whole-mount pathology. Each patient underwent evaluation with baseline TRUS and again during CE-TRUS with intravenous infusion of perflutren lipid microsphere (Definity®, Lantheus Medical Imaging, N Billerica, MA). A subjective 5 point scale was used to rate each sextant of the prostate in 3 baseline imaging modes (grayscale, color & power Doppler) and in 5 contrast-enhanced imaging modes (continuous harmonic, intermittent harmonic, flash replenishment, and color & power Doppler). Pathology maps of the prostate were digitized, and tumor volumes were measured in each sextant. Baseline TRUS and CE-TRUS findings were compared with whole-mount findings on a per-sextant basis. A clustered logistic regression model was computed to compare the area under the receiver operating characteristic curve (Az) for detection of prostate cancer by various modes of ultrasound imaging. RESULTS Among the 58 whole mount specimens, a maximum Gleason score of 6 was identified in 29 subjects, a score of 7 was identified in 24 and a score of 8 was identified in 5. Percent gland involvement was <2% (less than 1cc tumor volume) in 8 subjects, 2-5% in 19, 5-10% in 14, and >10% in 17. The Az for baseline TRUS parameters was 0.55 for grayscale, 0.61 for color Doppler and 0.59 for power Doppler. CE-TRUS parameters demonstrated significant increases in Az with the highest Az for CE-power Doppler (0.66) and flash replenishment imaging (0.64) (p=0.04 for comparison to baseline). When the evaluation was limited to subjects with >2% gland involvement, Az values were slightly higher for CE-TRUS, with the highest Az for CE-power Doppler (0.69) and flash replenishment imaging (0.65). The combination of CE-power Doppler and flash replenishment imaging resulted in improved Az as compared with baseline imaging (0.70 vs. 0.59, p=0.006). CONCLUSION Contrast-enhanced ultrasonography demonstrates greater diagnostic accuracy than baseline imaging. Diagnostic accuracy is further improved for "clinically significant" tumor volumes >1cc. CLINICAL RELEVANCE/APPLICATION CE-TRUS can improve the detection of prostate cancers with clinically relevant tumor volumes.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
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    ABSTRACT: Purpose The identification of clinically significant disease is crucial for optimal treatment of prostate cancer. Selective detection of prostate cancer with increased microvessel density is possible with contrast enhanced ultrasound. Preliminary studies suggest that pretreatment with a 5α-reductase inhibitor may improve the efficiency of contrast enhanced ultrasound targeted biopsy. This study was designed to quantify prostate cancer detection with contrast enhanced ultrasound with or without short-term pretreatment with dutasteride. Materials and Methods In this randomized, double-blind, placebo controlled trial of oral dutasteride pretreatment, contrast enhanced ultrasound findings were graded and used to direct targeted biopsy (up to 6 cores per prostate). A blinded 12-core systematic biopsy was subsequently performed on every subject based on standard medial and lateral sampling of each sextant. Results Of 311 subjects who underwent randomization, 272 completed participation. Positive biopsies were obtained in 276 of 3,264 (8.5%) systematic cores and 203 of 1,237 (16.4%) targeted cores (OR 2.1, 95% CI 1.7–2.6, p <0.001). ROC analysis for the detection of all prostate cancers demonstrated an increase in diagnostic accuracy from pre-contrast imaging to contrast enhanced ultrasound (Az 0.60 vs 0.64, p = 0.005). For the detection of high grade cancer (Gleason score 7 or greater) ROC analysis demonstrated improved accuracy for pre-contrast imaging (Az 0.74) and contrast enhanced ultrasound (Az 0.80, p = 0.0005). For the detection of high grade cancer with greater than 50% biopsy core involvement, excellent accuracy was demonstrated with pre-contrast and contrast enhanced ultrasound, Az 0.83 and 0.90, respectively (p = 0.001). Pretreatment with dutasteride had no significant impact on the detection of prostate cancer (p = 0.97). Conclusions Contrast enhanced ultrasound targeted biopsy provides a significant benefit for the detection of high grade/high volume prostate cancer.
    The Journal of urology 11/2012; 188(5):1739–1745. · 3.75 Impact Factor
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    ABSTRACT: Studies suggest that electrocardiographically gated coronary computed tomographic angiography provides a clear definition of the left ventricular outflow tract (LVOT), and normal LVOT morphology may not be round, as assumed when the continuity equation is applied during echocardiography. The aims of this study were to demonstrate the morphology of the LVOT on coronary computed tomographic angiography and to establish normal values for LVOT measurements. Two independent readers retrospectively measured anterior-posterior (AP) and transverse diameters of the LVOT and performed LVOT planimetry on coronary computed tomographic angiographic studies of 106 consecutive patients with normal aortic valves. Excellent interobserver agreement was observed for all measurements (r = 0.78-0.94). The LVOT was ovoid, with a larger transverse diameter than AP diameter during diastole and systole (P < .001). However, the ratio of AP diameter to transverse diameter was closer to 1.0 during systole (P < .001). Mean indexed LVOT area was minimally larger in systole than in diastole (P = .01-.04) and was larger in men than in women during diastole (P ≤ .001) and systole (P ≤ .01). Mean LVOT area indexed to body surface area was 2.3 ± 0.5 cm(2)/m(2) in women and 2.6 ± 0.7 cm(2)/m(2) in men. LVOT area demonstrated significant correlation with aortic root diameter. The normal LVOT is ovoid in shape. LVOT is more circular during systole, but the AP diameter remains smaller than the transverse diameter throughout the cardiac cycle. The oval shape of the LVOT has important implications when LVOT area is calculated from LVOT diameters. Normal LVOT area values established in this study should facilitate diagnosis of the fixed component of LVOT obstruction.
    Academic radiology 07/2012; 19(10):1252-9. · 2.09 Impact Factor
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    ABSTRACT: Traditional grayscale ultrasonography has poor discrimination between benign and malignant areas within the prostate. Current biopsy techniques commonly miss prostate cancer when present within the gland, with the majority of prostate biopsies negative for cancer. Enhanced ultrasound (US) modalities may improve the visualization of the prostate and better detect foci of prostate cancer. These enhanced US modalities include intravenous contrast enhancement, to better visualize areas with increased blood flow within the prostate, which may be indicative of latent prostate cancer. We reviewed the current literature for contrast-enhanced transrectal prostate ultrasonography. Numerous American and international studies demonstrate improved prostate cancer detection when contrast-enhanced US biopsy techniques are used. Enhanced US modalities include the use of harmonic imaging and flash replenishment techniques, as well as quantitative measurement of blood flow within the prostate. Vascular areas visualized with these techniques targeted for prostate biopsy yield improved prostate cancer detection rates. US contrast microbubbles linked to antibodies or small molecules may also allow targeted visualization and delivery of agents to the prostate. Enhanced US modalities with intravenous contrast enhancement dramatically improve vascular imaging and resolution within the prostate. Targeted biopsies have higher yield for prostate cancer detection, and may prove useful for the initial evaluation of patients with elevated serum prostate-specific antigen levels, as well as for patients with persistently elevated prostate-specific antigen after negative prostate biopsy.
    Current opinion in urology 05/2012; 22(4):303-9. · 2.50 Impact Factor
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    ABSTRACT: Objectives. To evaluate prostate cancer (PCa) detection rates of real-time elastography (RTE) in dependence of tumor size, tumor volume, localization and histological type. Materials and Methods. Thirdy-nine patients with biopsy proven PCa underwent RTE before radical prostatectomy (RPE) to assess prostate tissue elasticity, and hard lesions were considered suspicious for PCa. After RPE, the prostates were prepared as whole-mount step sections and were compared with imaging findings for analyzing PCa detection rates. Results. RTE detected 6/62 cancer lesions with a maximum diameter of 0-5 mm (9.7%), 10/37 with a maximum diameter of 6-10 mm (27%), 24/34 with a maximum diameter of 11-20 20 mm (70.6%), 14/14 with a maximum diameter of >20 mm (100%) and 40/48 with a volume ≥0.2 cm(3) (83.3%). Regarding cancer lesions with a volume ≥ 0.2 cm³ there was a significant difference in PCa detection rates between Gleason scores with predominant Gleason pattern 3 compared to those with predominant Gleason pattern 4 or 5 (75% versus 100%; P = 0.028). Conclusions. RTE is able to detect PCa of significant tumor volume and of predominant Gleason pattern 4 or 5 with high confidence, but is of limited value in the detection of small cancer lesions.
    The Scientific World Journal 01/2012; 2012:193213. · 1.73 Impact Factor
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    ABSTRACT: To evaluate enhanced transrectal ultrasound (E-TRUS) techniques including real-time sonoelastography (RTE) and contrast-enhanced transrectal ultrasound (CE-TRUS) for prostate cancer (PCa) detection in men with elevated prostate-specific antigen (PSA) serum levels. A total of 133 men with elevated PSA serum levels (≥1.25 ng/mL) showed PCa suspicious lesions on E-TRUS. RTE was done to assess tissue elasticity, and hard areas of the peripheral zone were considered suspicious for malignancy. CE-TRUS was done with cadence contrast pulse sequencing (CPS) technique to assess tumor neoangiogenesis, which were defined as areas with increased and rapid contrast enhancement in the peripheral zone and were considered suspicious for malignancy. All patients underwent an E-TRUS-targeted biopsy of the prostate into the suspected lesions. PCa detection rates for E-TRUS were analyzed. PCa detection rate of E-TRUS-targeted biopsy was 59.4% (79/133) using a median of 5 cores per patient and a median of 3 cores per lesion. RTE showed a per patient detection rate of 56.5% (70/124) and CE-TRUS of 74.2% (69/93). The subgroup analysis demonstrated the highest detection rates in prostate volumes <40 mL (72.2%) and in men older than 70 years (87%). The combined use of CE-TRUS and RTE is feasible and allows for targeted biopsy and may improve PCa detection.
    World Journal of Urology 12/2011; 30(3):341-6. · 2.89 Impact Factor
  • Ethan J. Halpern
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    ABSTRACT: PURPOSE Left ventricular (LV) mass is an independent predictor of clinical outcome for cardiovascular disease, but its utility is limited by the variability of echocardiographic LV mass calculation. Quantification of LV mass by transthoracic echocardiography (TTE) is most frequently accomplished with a cubed formula that incorporates only short axis measurements of the LV cavity and assumes an ellipsoid geometry. We compared LV mass based upon short axis TTE measurements with volumetric measurements obtained by coronary CT angiography (CCTA) during systole and diastole. Additionally, we evaluated whether short axis TTE quantification could be improved by introducing a correction factor for ventricular length as measured during CCTA. METHOD AND MATERIALS TTE and ECG-gated CCTA were performed within 30 days on each of 41 patients. LV mass was computed from short axis TTE images based upon the cubed formula advocated in the standards of the American Society of Echocardiography. CCTA was performed with a Brilliance CT scanner (Philips Medical Systems). LV mass on CCTA was computed at both end-diastole and end-systole as the difference in calculated volumes within the epicardial and endocardial outlines of the left ventricle. Pearson correlation was computed between TTE and CCTA calculations of LV mass. In an attempt to improve this correlation we introduced a correction factor into the echocardiographic calculation based upon the LV long axis dimension of each patient as measured on CCTA, and calculated a “corrected” LV mass. RESULTS Excellent correlation was obtained between systolic and diastolic LV mass computed from CCTA (correlation coefficient = 0.87), suggesting that CCTA provides a reproducible measure of LV mass. Correlation between LV mass obtained by TTE and CCTA was fair (correlation coefficients: 0.56-0.64). Addition of LV long axis dimension to compute a corrected LV mass by echocardiography produced only minimal improvement in agreement between TTE and CCTA (correlation coefficients: 0.61-0.69; p > 0.3). CONCLUSION Gated CCTA provides reproducible estimates of LV mass during systole and diastole. Estimates of LV mass by TTE differ from LV mass estimates by CCTA because of complex geometric factors that are not corrected by measurement of LV length. CLINICAL RELEVANCE/APPLICATION Estimates of LV mass by CCTA provide a reliable measurement that is independent of the phase of the cardiac cycle.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 12/2011
  • Ethan J. Halpern, David J. Halpern, David H Wiener
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    ABSTRACT: PURPOSE A diagnosis of left ventricular outflow tract (LVOT) obstruction is suggested in the setting of a normal aortic valve with an elevated gradient in the left ventricular outflow tract. LVOT obstruction is classically associated with left ventricular hypertrophy (LVH) and dynamic ventricular function. We recently encountered a symptomatic adult patient with LVOT obstruction based upon a Doppler gradient, but without LVH. Echocardiographic visualization of the LVOT was limited. Cardiac CT demonstrated an LVOT area of 2.2sq cm by planimetry (diameters: 2.1 x 1.5cm) with associated systolic anterior motion of the mitral leaflets. However, normal values of LVOT area were not available in the literature to validate that our patient had subaortic obstruction on the basis of a small LVOT. This study was performed to establish a normal range for LVOT diameters and area. METHOD AND MATERIALS A retrospective review was performed of 100 cardiac CT angiography studies performed for the evaluation of chest pain (iCT scanner; Philips Medical Systems). All patients had a normal aortic valve with no history of aortic stenosis. Short axis views of the LVOT were obtained at end systole (40% of the R-R interval) by identifying the LVOT on a standard three chamber long axis view and rotating the volume 90°. Measurements of the transverse and antero-posterior diameter of the LVOT were obtained along with planimetry of the LVOT area. RESULTS The LVOT was clearly visualized on all CT studies. The adult LVOT measured during systole is oval in shape, with a larger transverse diameter (2.8cm ± 0.20) as compared to the antero-posterior diameter (2.1cm ± 0.25), p<0.001. The mean normal LVOT area by planimetry measured 4.6sq cm ± 0.86. Thus, the LVOT measurements of our patient with subaortic stenosis were approximately 3 standard deviations below the mean (see figure: patient on top row; normal control below). CONCLUSION The LVOT is well visualized and easily defined on ECG-gated cardiac CT. Our study provides normal values for LVOT diameters and area. CLINICAL RELEVANCE/APPLICATION A small LVOT may be useful to explain dynamic LVOT obstruction in patients who present with an LVOT gradient.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011
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    ABSTRACT: PURPOSE There have been substantial changes in CPT coding and reimbursement for stress testing, coronary CT angiography (cCTA) and conventional coronary angiography between the 2009, 2010 and 2011 Medicare fee schedules. We employed a decision analytic model to evaluate diagnostic accuracy and imaging costs for the diagnosis of coronary artery disease (CAD), and to evaluate how changes in the fee schedule might impact the cost-effectiveness of different work-up strategies. METHOD AND MATERIALS Our decision model utilizes stress testing (stress ECG, stress Echo, or stress myocardial perfusion scintigraphy (MPS)) and cCTA for evaluation of suspected CAD. All possible combinations of stress tests and cCTA were evaluated. Patients with a positive stress/cCTA evaluation undergo cardiac catheterization. Values of sensitivity and specificity for stress tests and cCTA from the published literature were entered into a decision tree. Costs were evaluated as a function of CAD prevalence based upon Medicare fee schedules from 2009, 2010 and 2011. RESULTS The combination of cCTA with any stress study results in a decreased false positive rate (FPR) relative to a stress study alone. FPR is minimized when cCTA is combined with stress echocardiography. Reimbursement for cCTA was reduced each year from 2009-2011, with an overall reduction of 39%. Reimbursement for other stress studies was reduced by 7-12% over the same two year period. A stress test followed by cCTA results in lower imaging costs as compared to stress testing alone for any disease prevalence below 60-70%. Imaging costs are minimized by a strategy that employs stress ECG followed by cCTA. MPS alone is the most expensive diagnostic option for evaluation of CAD, and has become increasingly more expensive as compared to other options based upon changing reimbursement from 2009-2011. CONCLUSION Changes in CPT coding and fee schedules have reduced the reimbursements for stress tests and cCTA in the 2009 - 2011 Medicare fee schedules. Work-up strategies that begin with stress ECG or stress Echo and progress to cCTA (if the stress test is positive) represent the least expensive options, and are more cost-effective relative to strategies that utilize MPS. CLINICAL RELEVANCE/APPLICATION The evaluation of coronary disease may be optimized by an appropriate combination of stress testing and cCTA to reduce imaging costs and unnecessary cardiac catheterizations.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011

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2k Citations
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Institutions

  • 1995–2014
    • Thomas Jefferson University
      • • Department of Radiology
      • • Department of Urology
      Philadelphia, Pennsylvania, United States
  • 1994–2014
    • Thomas Jefferson University Hospitals
      • Department of Radiology
      Philadelphia, Pennsylvania, United States
  • 2004–2012
    • Medizinische Universität Innsbruck
      • • Univ.-Klinik für Radiologie
      • • Univ.-Klinik für Urologie
      Innsbruck, Tyrol, Austria
  • 2003
    • University of Innsbruck
      • Institute of Biochemistry
      Innsbruck, Tyrol, Austria
  • 1997–1998
    • Drexel University
      • Department of Electrical and Computer Engineering
      Philadelphia, PA, United States
  • 1996
    • University of Houston
      Houston, Texas, United States