36 results on '"Cohan RH"'
Search Results
2. Apprenticeships ease the transition to independent call an evaluation of anxiety and confidence among junior radiology residents.
- Author
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Trout AT, Wang PI, Cohan RH, Bailey JE, Khalatbari S, Myles JD, and Dunnick NR
- Published
- 2011
3. Survival Prediction of Patients with Bladder Cancer after Cystectomy Based on Clinical, Radiomics, and Deep-Learning Descriptors.
- Author
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Sun D, Hadjiiski L, Gormley J, Chan HP, Caoili EM, Cohan RH, Alva A, Gulani V, and Zhou C
- Abstract
Accurate survival prediction for bladder cancer patients who have undergone radical cystectomy can improve their treatment management. However, the existing predictive models do not take advantage of both clinical and radiological imaging data. This study aimed to fill this gap by developing an approach that leverages the strengths of clinical (C), radiomics (R), and deep-learning (D) descriptors to improve survival prediction. The dataset comprised 163 patients, including clinical, histopathological information, and CT urography scans. The data were divided by patient into training, validation, and test sets. We analyzed the clinical data by a nomogram and the image data by radiomics and deep-learning models. The descriptors were input into a BPNN model for survival prediction. The AUCs on the test set were (C): 0.82 ± 0.06, (R): 0.73 ± 0.07, (D): 0.71 ± 0.07, (CR): 0.86 ± 0.05, (CD): 0.86 ± 0.05, and (CRD): 0.87 ± 0.05. The predictions based on D and CRD descriptors showed a significant difference (p = 0.007). For Kaplan-Meier survival analysis, the deceased and alive groups were stratified successfully by C (p < 0.001) and CRD (p < 0.001), with CRD predicting the alive group more accurately. The results highlight the potential of combining C, R, and D descriptors to accurately predict the survival of bladder cancer patients after cystectomy.
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- 2023
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4. Computerized Decision Support for Bladder Cancer Treatment Response Assessment in CT Urography: Effect on Diagnostic Accuracy in Multi-Institution Multi-Specialty Study.
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Sun D, Hadjiiski L, Alva A, Zakharia Y, Joshi M, Chan HP, Garje R, Pomerantz L, Elhag D, Cohan RH, Caoili EM, Kerr WT, Cha KH, Kirova-Nedyalkova G, Davenport MS, Shankar PR, Francis IR, Shampain K, Meyer N, Barkmeier D, Woolen S, Palmbos PL, Weizer AZ, Samala RK, Zhou C, and Matuszak M
- Subjects
- Artificial Intelligence, Humans, Tomography, X-Ray Computed, Urography, Decision Support Systems, Clinical, Urinary Bladder Neoplasms diagnostic imaging, Urinary Bladder Neoplasms therapy
- Abstract
This observer study investigates the effect of computerized artificial intelligence (AI)-based decision support system (CDSS-T) on physicians' diagnostic accuracy in assessing bladder cancer treatment response. The performance of 17 observers was evaluated when assessing bladder cancer treatment response without and with CDSS-T using pre- and post-chemotherapy CTU scans in 123 patients having 157 pre- and post-treatment cancer pairs. The impact of cancer case difficulty, observers' clinical experience, institution affiliation, specialty, and the assessment times on the observers' diagnostic performance with and without using CDSS-T were analyzed. It was found that the average performance of the 17 observers was significantly improved ( p = 0.002) when aided by the CDSS-T. The cancer case difficulty, institution affiliation, specialty, and the assessment times influenced the observers' performance without CDSS-T. The AI-based decision support system has the potential to improve the diagnostic accuracy in assessing bladder cancer treatment response and result in more consistent performance among all physicians.
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- 2022
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5. Cocaine nephropathy: A rare cause of abnormal nephrograms.
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Lamberg H, Cohan RH, and Millet JD
- Abstract
Cocaine use is associated with a variety of renal injuries. Although rhabdomyolysis is the most common cause of cocaine-induced nephropathy, cocaine can also cause renal vasculitis, acute interstitial nephritis, acute tubular necrosis, thrombotic microangiopathy, and renal infarction. We present a rare case of cocaine-induced nephropathy in a 30-year-old male who presented with acute kidney injury and abnormal nephrograms at contrast-enhanced computed tomography. Mechanisms of cocaine-induced renal injury and differential causes of abnormal nephrograms encountered at imaging are discussed. Cocaine-induced nephropathy is a rare but important cause of abnormal nephrograms and should be considered in the differential diagnosis when clinically appropriate., (© 2021 Published by Elsevier Inc. on behalf of University of Washington.)
- Published
- 2021
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6. Video Interviewing: A Review and Recommendations for Implementation in the Era of COVID-19 and Beyond.
- Author
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Joshi A, Bloom DA, Spencer A, Gaetke-Udager K, and Cohan RH
- Subjects
- COVID-19, Humans, Internship and Residency, Interviews as Topic, Personnel Selection, SARS-CoV-2, Betacoronavirus, Coronavirus Infections, Pandemics, Pneumonia, Viral
- Abstract
Due to the COVID-19 pandemic, it is very likely that many radiology residency and fellowship programs will adopt interactive videoconference interviewing for the 2020-2021 residency match cycle. Although video interviewing has become a common part of the hiring process for business, experience with video interviewing for resident and fellow selection has been limited. Advantages of video interviews over traditional on-site interviews include cost-savings to both applicants and residency programs, less disruption to an applicant's educational activities, and potential for training programs to access a wider pool of candidates. The loss of the casual interactions that occur during an on-site interview and the inability of candidates to evaluate training facilities and their surrounding environments in-person are among the obstacles posed by video interviews, but training programs can mitigate these challenges with enhanced website content and creative media solutions. Through a review of the existing literature and internet resources, this article recommends specific measures medical schools, applicants, and radiology residency and fellowship programs can take to optimize the virtual interview experience for all involved parties., Competing Interests: Declaration of Competing Interest None, (Copyright © 2020 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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7. Intraobserver Variability in Bladder Cancer Treatment Response Assessment With and Without Computerized Decision Support.
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Hadjiiski LM, Cha KH, Cohan RH, Chan HP, Caoili EM, Davenport MS, Samala RK, Weizer AZ, Alva A, Kirova-Nedyalkova G, Shampain K, Meyer N, Barkmeier D, Woolen SA, Shankar PR, Francis IR, and Palmbos PL
- Subjects
- Humans, Observer Variation, Physicians, Tomography, X-Ray Computed, Decision Support Systems, Clinical, Urinary Bladder Neoplasms diagnostic imaging, Urinary Bladder Neoplasms drug therapy
- Abstract
We evaluated the intraobserver variability of physicians aided by a computerized decision-support system for treatment response assessment (CDSS-T) to identify patients who show complete response to neoadjuvant chemotherapy for bladder cancer, and the effects of the intraobserver variability on physicians' assessment accuracy. A CDSS-T tool was developed that uses a combination of deep learning neural network and radiomic features from computed tomography (CT) scans to detect bladder cancers that have fully responded to neoadjuvant treatment. Pre- and postchemotherapy CT scans of 157 bladder cancers from 123 patients were collected. In a multireader, multicase observer study, physician-observers estimated the likelihood of pathologic T0 disease by viewing paired pre/posttreatment CT scans placed side by side on an in-house-developed graphical user interface. Five abdominal radiologists, 4 diagnostic radiology residents, 2 oncologists, and 1 urologist participated as observers. They first provided an estimate without CDSS-T and then with CDSS-T. A subset of cases was evaluated twice to study the intraobserver variability and its effects on observer consistency. The mean areas under the curves for assessment of pathologic T0 disease were 0.85 for CDSS-T alone, 0.76 for physicians without CDSS-T and improved to 0.80 for physicians with CDSS-T ( P = .001) in the original evaluation, and 0.78 for physicians without CDSS-T and improved to 0.81 for physicians with CDSS-T ( P = .010) in the repeated evaluation. The intraobserver variability was significantly reduced with CDSS-T ( P < .0001). The CDSS-T can significantly reduce physicians' variability and improve their accuracy for identifying complete response of muscle-invasive bladder cancer to neoadjuvant chemotherapy., Competing Interests: Conflict of Interest: None reported., (© 2020 The Authors. Published by Grapho Publications, LLC.)
- Published
- 2020
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8. Diagnostic Accuracy of CT for Prediction of Bladder Cancer Treatment Response with and without Computerized Decision Support.
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Cha KH, Hadjiiski LM, Cohan RH, Chan HP, Caoili EM, Davenport MS, Samala RK, Weizer AZ, Alva A, Kirova-Nedyalkova G, Shampain K, Meyer N, Barkmeier D, Woolen S, Shankar PR, Francis IR, and Palmbos P
- Subjects
- Adult, Aged, Aged, 80 and over, Area Under Curve, Chemotherapy, Adjuvant, Decision Support Systems, Clinical, Deep Learning, Female, Humans, Immunoglobulin G therapeutic use, Male, Melphalan therapeutic use, Middle Aged, Neoadjuvant Therapy, Neoplasm Invasiveness, Neoplasm Staging, ROC Curve, Retrospective Studies, Treatment Outcome, Urinary Bladder Neoplasms pathology, Radiographic Image Interpretation, Computer-Assisted methods, Tomography, X-Ray Computed, Urinary Bladder Neoplasms diagnostic imaging, Urinary Bladder Neoplasms drug therapy
- Abstract
Rationale and Objectives: To evaluate whether a computed tomography (CT)-based computerized decision-support system for muscle-invasive bladder cancer treatment response assessment (CDSS-T) can improve identification of patients who have responded completely to neoadjuvant chemotherapy., Materials and Methods: Following Institutional Review Board approval, pre-chemotherapy and post-chemotherapy CT scans of 123 subjects with 157 muscle-invasive bladder cancer foci were collected retrospectively. CT data were analyzed with a CDSS-T that uses a combination of deep-learning convolutional neural network and radiomic features to distinguish muscle-invasive bladder cancers that have fully responded to neoadjuvant treatment from those that have not. Leave-one-case-out cross-validation was used to minimize overfitting. Five attending abdominal radiologists, four diagnostic radiology residents, two attending oncologists, and one attending urologist estimated the likelihood of pathologic T0 disease (complete response) by viewing paired pre/post-treatment CT scans placed side-by-side on an internally-developed graphical user interface. The observers provided an estimate without use of CDSS-T and then were permitted to revise their estimate after a CDSS-T-derived likelihood score was displayed. Observer estimates were analyzed with multi-reader, multi-case receiver operating characteristic methodology. The area under the curve (AUC) and the statistical significance of the difference were estimated., Results: The mean AUCs for assessment of pathologic T0 disease were 0.80 for CDSS-T alone, 0.74 for physicians not using CDSS-T, and 0.77 for physicians using CDSS-T. The increase in the physicians' performance was statistically significant (P < .05)., Conclusion: CDSS-T improves physician performance for identifying complete response of muscle-invasive bladder cancer to neoadjuvant chemotherapy., (Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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9. Deep Learning Approach for Assessment of Bladder Cancer Treatment Response.
- Author
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Wu E, Hadjiiski LM, Samala RK, Chan HP, Cha KH, Richter C, Cohan RH, Caoili EM, Paramagul C, Alva A, and Weizer AZ
- Subjects
- Antineoplastic Agents therapeutic use, Cystectomy, Decision Support Systems, Clinical, Drug Monitoring methods, Humans, Neoadjuvant Therapy methods, ROC Curve, Radiographic Image Interpretation, Computer-Assisted methods, Sensitivity and Specificity, Tomography, X-Ray Computed methods, Transfer, Psychology, Treatment Outcome, Urography methods, Deep Learning, Urinary Bladder Neoplasms diagnostic imaging, Urinary Bladder Neoplasms drug therapy
- Abstract
We compared the performance of different Deep learning-convolutional neural network (DL-CNN) models for bladder cancer treatment response assessment based on transfer learning by freezing different DL-CNN layers and varying the DL-CNN structure. Pre- and posttreatment computed tomography scans of 123 patients (cancers, 129; pre- and posttreatment cancer pairs, 158) undergoing chemotherapy were collected. After chemotherapy 33% of patients had T0 stage cancer (complete response). Regions of interest in pre- and posttreatment scans were extracted from the segmented lesions and combined into hybrid pre -post image pairs (h-ROIs). Training (pairs, 94; h-ROIs, 6209), validation (10 pairs) and test sets (54 pairs) were obtained. The DL-CNN consisted of 2 convolution (C1-C2), 2 locally connected (L3-L4), and 1 fully connected layers. The DL-CNN was trained with h-ROIs to classify cancers as fully responding (stage T0) or not fully responding to chemotherapy. Two radiologists provided lesion likelihood of being stage T0 posttreatment. The test area under the ROC curve (AUC) was 0.73 for T0 prediction by the base DL-CNN structure with randomly initialized weights. The base DL-CNN structure with pretrained weights and transfer learning (no frozen layers) achieved test AUC of 0.79. The test AUCs for 3 modified DL-CNN structures (different C1-C2 max pooling filter sizes, strides, and padding, with transfer learning) were 0.72, 0.86, and 0.69. For the base DL-CNN with (C1) frozen, (C1-C2) frozen, and (C1-C2-L3) frozen, the test AUCs were 0.81, 0.78, and 0.71, respectively. The radiologists' AUCs were 0.76 and 0.77. DL-CNN performed better with pretrained than randomly initialized weights.
- Published
- 2019
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10. Productivity, Meet Burnout.
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Cohan RH and Davenport MS
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- 2018
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11. A pictorial review of bladder cancer nodal metastases.
- Author
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Shankar PR, Barkmeier D, Hadjiiski L, and Cohan RH
- Abstract
Lymph node involvement in bladder cancer is common and has prognostic implications. Early and accurate identification of metastatic lymph nodes is, therefore, important in ensuring appropriate patient triage and management. The purpose of this review is to provide a pictorial and educational overview of the staging and imaging appearance of metastatic lymph nodes in bladder cancer. Additionally, a secondary aim of this manuscript is to provide a review of the diagnostic accuracy of common imaging modalities available for detecting metastatic lymph nodes in affected patients., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.
- Published
- 2018
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12. (Lack of) Measurable Clinical or Knowledge Gains From Resident Participation in Noon Conference.
- Author
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Meyer NB, Gaetke-Udager K, Shampain KL, Spencer A, Cohan RH, and Davenport MS
- Subjects
- Cross-Sectional Studies, Data Collection, Health Knowledge, Attitudes, Practice, Humans, Retrospective Studies, Academic Performance, Clinical Competence, Internship and Residency methods, Radiology education
- Abstract
Rationale and Objectives: The objective of this study was to determine whether noon conference attendance by diagnostic radiology residents is predictive of measurable performance., Methods: This single-center retrospective Health Insurance and Portability and Accountability Act (HIPAA)-compliant cross-sectional study was considered "not regulated" by the institutional review board. All diagnostic radiology residents who began residency training from 2008 to 2012 were included (N = 54). Metrics of clinical performance and knowledge were collected, including junior and senior precall test results, American Board of Radiology scores (z-score transformed), American College of Radiology in-training scores (years 1-3), on-call "great call" and minor and major discrepancy rates, on-call and daytime case volumes, and training rotation scores. Multivariate regression models were constructed to determine if conference attendance, match rank order, or starting year could predict these outcomes. Pearson bivariate correlations were calculated., Results: Senior precall test results were moderately correlated with American Board of Radiology (r = 0.41) and American College of Radiology (r = 0.38-0.48) test results and mean rotation scores (r = 0.41), indicating moderate internal validity. However, conference attendance, match rank order, and year of training did not correlate with (r = -0.16-0.16) or predict (P > .05) measurable resident knowledge. On multivariate analysis, neither match rank order (P = .14-.96) nor conference attendance (P = .10-.88) predicted measurable clinical efficiency or accuracy. Year started training predicted greater cross-sectional case volume (P < .0001, β = 0.361-0.516) and less faculty-to-resident feedback (P < 0.0001, β = [-0.628]-[-0.733])., Conclusions: Residents with lower conference attendance are indistinguishable from those who attend more frequently in a wide range of clinical and knowledge-based performance assessments, suggesting that required attendance may not be necessary to gain certain measurable core competencies., (Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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13. Expanding the Definition of a Benign Renal Cyst on Contrast-enhanced CT: Can Incidental Homogeneous Renal Masses Measuring 21-39 HU be Safely Ignored?
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Hu EM, Ellis JH, Silverman SG, Cohan RH, Caoili EM, and Davenport MS
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- Adult, Aged, Contrast Media, Female, Humans, Incidental Findings, Male, Middle Aged, Retrospective Studies, Kidney Diseases, Cystic diagnostic imaging, Kidney Neoplasms diagnostic imaging, Tomography, X-Ray Computed
- Abstract
Rationale and Objective: We aimed to determine the frequency and clinical significance of homogeneous renal masses measuring 21-39 Hounsfield units on contrast-enhanced computed tomography (CT)., Methods: Subjects 40-69 years old undergoing portal-venous-phase contrast-enhanced abdominal CT from January 1, 2006 to December 31, 2010 with slice thickness ≤5 mm and no prior CT or magnetic resonance imaging were identified (n = 1387) for this institutional review board-approved retrospective cohort study. Images were manually reviewed by three radiologists in consensus to identify all circumscribed homogeneous renal masses (maximum of three per subject) ≥10 mm with a measured attenuation of 21-39 Hounsfield units. Exclusion criteria were known renal cancer or imaging performed for a renal indication. The primary outcome was retrospective characterization as a clinically significant mass, defined as a solid mass, a Bosniak IIF/III/IV mass, or extirpative therapy or metastatic renal cancer within 5 years' follow-up., Results: Eligible masses (n = 74) were found in 5% (63/1387) of subjects. Of those with a reference standard (n = 42), none (0% [95% CI: 0.0%-8.4%]) were determined to be clinically significant., Conclusion: Incidental renal masses on contrast-enhanced CT that are homogeneous and display an attenuation of 21-39 Hounsfield units are uncommon in patients 40-69 years of age, unlikely to be clinically significant, and may not need further imaging evaluation. If these results can be replicated in an independent and larger population, the practical definition of a benign cyst on imaging may be able to be expanded., (Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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14. Renal Tumors
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Aganovic L, Cohan RH, Hodler J, Kubik-Huch RA, and von Schulthess GK
- Abstract
Cystic and solid renal masses can be imaged with ultrasound, CT, and MRI, with contrast enhancement needed to optimize renal mass detection and characterization. Most very small renal masses cannot be characterized due to their size. Because the overwhelming majority of these are benign, follow-up is suggested only when these masses appear heterogeneous. CT and MRI are able to predict which cystic renal masses are most likely to be malignant. CT and MRI can identify macroscopic fat in the vast majority of angiomyolipomas, allowing for differentiation from other solid renal masses. Although some solid renal masses without macroscopic fat may contain distinct combinations of imaging features, there is much overlap, and biopsy will often be required for diagnosis. CT and MRI are accurate in staging renal cancers, predicting whether partial nephrectomy can be performed successfully, and for imaging patients after treatment. Unique patterns of metastatic disease response can be encountered after treatment of metastatic renal cancer with targeted chemotherapeutic agents. Radiologists must be aware of these patterns as well as of the imaging appearance of newly emerging treatment complications., (Copyright 2018, The Author(s).)
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- 2018
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15. Bladder Cancer Treatment Response Assessment in CT using Radiomics with Deep-Learning.
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Cha KH, Hadjiiski L, Chan HP, Weizer AZ, Alva A, Cohan RH, Caoili EM, Paramagul C, and Samala RK
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- Adult, Aged, Aged, 80 and over, Female, Humans, Image Processing, Computer-Assisted, Male, Middle Aged, ROC Curve, Treatment Outcome, Deep Learning, Medical Informatics methods, Tomography, X-Ray Computed, Urinary Bladder Neoplasms diagnosis, Urinary Bladder Neoplasms therapy
- Abstract
Cross-sectional X-ray imaging has become the standard for staging most solid organ malignancies. However, for some malignancies such as urinary bladder cancer, the ability to accurately assess local extent of the disease and understand response to systemic chemotherapy is limited with current imaging approaches. In this study, we explored the feasibility that radiomics-based predictive models using pre- and post-treatment computed tomography (CT) images might be able to distinguish between bladder cancers with and without complete chemotherapy responses. We assessed three unique radiomics-based predictive models, each of which employed different fundamental design principles ranging from a pattern recognition method via deep-learning convolution neural network (DL-CNN), to a more deterministic radiomics feature-based approach and then a bridging method between the two, utilizing a system which extracts radiomics features from the image patterns. Our study indicates that the computerized assessment using radiomics information from the pre- and post-treatment CT of bladder cancer patients has the potential to assist in assessment of treatment response.
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- 2017
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16. Bladder Cancer Segmentation in CT for Treatment Response Assessment: Application of Deep-Learning Convolution Neural Network-A Pilot Study.
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Cha KH, Hadjiiski LM, Samala RK, Chan HP, Cohan RH, Caoili EM, Paramagul C, Alva A, and Weizer AZ
- Abstract
Assessing the response of bladder cancer to neoadjuvant chemotherapy is crucial for reducing morbidity and increasing quality of life of patients. Changes in tumor volume during treatment is generally used to predict treatment outcome. We are developing a method for bladder cancer segmentation in CT using a pilot data set of 62 cases. 65 000 regions of interests were extracted from pre-treatment CT images to train a deep-learning convolution neural network (DL-CNN) for tumor boundary detection using leave-one-case-out cross-validation. The results were compared to our previous AI-CALS method. For all lesions in the data set, the longest diameter and its perpendicular were measured by two radiologists, and 3D manual segmentation was obtained from one radiologist. The World Health Organization (WHO) criteria and the Response Evaluation Criteria In Solid Tumors (RECIST) were calculated, and the prediction accuracy of complete response to chemotherapy was estimated by the area under the receiver operating characteristic curve (AUC). The AUCs were 0.73 ± 0.06, 0.70 ± 0.07, and 0.70 ± 0.06, respectively, for the volume change calculated using DL-CNN segmentation, the AI-CALS and the manual contours. The differences did not achieve statistical significance. The AUCs using the WHO criteria were 0.63 ± 0.07 and 0.61 ± 0.06, while the AUCs using RECIST were 0.65 ± 007 and 0.63 ± 0.06 for the two radiologists, respectively. Our results indicate that DL-CNN can produce accurate bladder cancer segmentation for calculation of tumor size change in response to treatment. The volume change performed better than the estimations from the WHO criteria and RECIST for the prediction of complete response.
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- 2016
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17. Optimizing the post-graduate institutional program evaluation process.
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Lypson ML, Prince ME, Kasten SJ, Osborne NH, Cohan RH, Kowalenko T, Dougherty PJ, Reynolds RK, Spires MC, Kozlow JH, and Gitlin SD
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- Focus Groups, Humans, Interviews as Topic, Program Evaluation methods, Quality Improvement organization & administration, United Kingdom, Education, Medical, Graduate standards, Program Evaluation standards, Quality Improvement standards
- Abstract
Background: Reviewing program educational efforts is an important component of postgraduate medical education program accreditation. The post-graduate review process has evolved over time to include centralized oversight based on accreditation standards. The institutional review process and the impact on participating faculty are topics not well described in the literature., Methods: We conducted multiple Plan-Do-Study-Act (PDSA) cycles to identify and implement areas for change to improve productivity in our institutional program review committee. We also conducted one focus group and six in-person interviews with 18 committee members to explore their perspectives on the committee's evolution. One author (MLL) reviewed the transcripts and performed the initial thematic coding with a PhD level research associate and identified and categorized themes. These themes were confirmed by all participating committee members upon review of a detailed summary. Emergent themes were triangulated with the University of Michigan Medical School's Admissions Executive Committee (AEC)., Results: We present an overview of adopted new practices to the educational program evaluation process at the University of Michigan Health System that includes standardization of meetings, inclusion of resident members, development of area content experts, solicitation of committed committee members, transition from paper to electronic committee materials, and focus on continuous improvement. Faculty and resident committee members identified multiple improvement areas including the ability to provide high quality reviews of training programs, personal and professional development, and improved feedback from program trainees., Conclusions: A standing committee that utilizes the expertise of a group of committed faculty members and which includes formal resident membership has significant advantages over ad hoc or other organizational structures for program evaluation committees.
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- 2016
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18. Residents' ability to interpret radiology images: development and improvement of an assessment tool.
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Seagull FJ, Bailey JE, Trout A, Cohan RH, and Lypson ML
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- Internet, Radiology statistics & numerical data, Software, United States, Clinical Competence statistics & numerical data, Computer-Assisted Instruction statistics & numerical data, Diagnostic Imaging statistics & numerical data, Educational Measurement statistics & numerical data, Internship and Residency statistics & numerical data, Radiology education
- Abstract
Rationale and Objectives: Despite increasing radiology coverage, nonradiology residents continue to preliminarily interpret basic radiologic studies independently, yet their ability to do so accurately is not routinely assessed., Materials and Methods: An online test of basic radiologic image interpretation was developed through an iterative process. Educational objectives were established, then questions and images were gathered to create an assessment. The test was administered online to first-year interns (postgraduate year [PGY] 1) from 14 different specialties, as well as a sample of third- and fourth-year radiology residents (PGY3/R2 and PGY4/R3)., Results: Over a 2-year period, 368 residents were assessed, including PGY1 (n = 349), PGY3/R2 (n = 14), and PGY4/R3 (n = 5) residents. Overall, the test discriminated effectively between interns (average score = 66%) and advanced residents (R2 = 86%, R3 = 89%; P < .05). Item analysis indicated discrimination indices ranging from -0.72 to 48.3 (mean = 3.12, median 0.58) for individual questions, including four questions with negative discrimination indices. After removal of the negatively indexed questions, the overall predictive value of the instrument persisted and discrimination indices increased for all but one of the remaining questions (range 0.027-70.8, mean 5.76, median 0.94)., Conclusions: Validation of an initial iteration of an assessment of basic image-interpretation skills led to revisions that improved the test. The results offer a specific test of radiologic reading skills with validation evidence for residents. More generally, results demonstrate a principled approach to test development., (Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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19. Auto-initialized cascaded level set (AI-CALS) segmentation of bladder lesions on multidetector row CT urography.
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Hadjiiski L, Chan HP, Caoili EM, Cohan RH, Wei J, and Zhou C
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- Humans, Reproducibility of Results, Sensitivity and Specificity, Algorithms, Pattern Recognition, Automated methods, Radiographic Image Enhancement methods, Radiographic Image Interpretation, Computer-Assisted methods, Tomography, X-Ray Computed methods, Urinary Bladder Neoplasms diagnostic imaging, Urography methods
- Abstract
Rationale and Objectives: To develop a computerized system for segmentation of bladder lesions on computed tomography urography (CTU) scans for detection and characterization of bladder cancer., Materials and Methods: We have developed an auto-initialized cascaded level set method to perform bladder lesion segmentation. The segmentation performance was evaluated on a preliminary dataset including 28 CTU scans from 28 patients collected retrospectively with institutional review board approval. The bladders were partially filled with intravenous contrast material. The lesions were located fully or partially within the contrast-enhanced area or in the non-contrast-enhanced area of the bladder. An experienced abdominal radiologist marked 28 lesions (14 malignant and 14 benign) with bounding boxes that served as input to the automated segmentation system and assigned a difficulty rating on a scale of 1 to 5 (5 = most subtle) to each lesion. The contours from automated segmentation were compared to three-dimensional contours manually drawn by the radiologist. Three performance metric measures were used for comparison. In addition, the automated segmentation quality was assessed by an expert panel of two experienced radiologists, who provided quality ratings of the contours on a scale from 1 to 10 (10 = excellent)., Results: The average volume intersection ratio, the average absolute volume error, and the average distance measure were 67.2 ± 16.9%, 27.3 ± 26.9%, and 2.89 ± 1.69 mm, respectively. Of the 28 segmentations, 18 were given quality ratings of 8 or above. The average rating was 7.9 ± 1.5. The average quality ratings for lesions with difficulty ratings of 1, 2, 3, and 4 were 8.8 ± 0.9, 7.9 ± 1.8, 7.4 ± 0.9, and 6.6 ± 1.5, respectively., Conclusion: Our preliminary study demonstrates the feasibility of using the three-dimensional level set method for segmenting bladder lesions in CTU scans., (Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.)
- Published
- 2013
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20. Teaching management of contrast reactions: does it work and how often do we need to refresh?
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Trout AT, Cohan RH, Ellis JH, and Khalatbari S
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- Curriculum, Humans, Michigan, Contrast Media adverse effects, Drug-Related Side Effects and Adverse Reactions chemically induced, Drug-Related Side Effects and Adverse Reactions prevention & control, Educational Measurement, Internship and Residency statistics & numerical data, Radiology education, Teaching methods
- Abstract
Rationale and Objectives: Knowledge of the management of acute contrast reactions is lacking among radiologists. Training in the management of acute contrast reactions occurs at the investigators' institution and others, but the durability of that training and the need for refresher training have not been assessed., Materials and Methods: A prospective assessment of changes in trainees' knowledge and confidence following a required educational course concerning reactions to contrast material was conducted. Assessments were performed prior to and immediately following the course and at 1, 3, 6, and 9 months after the course., Results: Trainees' knowledge significantly improved following the course and remained improved for 6 months (P < .0001). By 9 months, knowledge was no longer improved over baseline (P = .0644). Trainees' confidence also improved following the course and remained improved throughout follow-up (P = .0356 at 9 months). At 6 months, however, confidence had significantly declined relative to levels immediately after the course (P = .0241). Trainees' knowledge was not dependent on postgraduate year (PGY), but PGY-2 residents were significantly less confident in their ability to manage a contrast reaction than PGY-5 and PGY-6 trainees. Trainees who managed contrast reactions during the follow-up period were more confident in their abilities than trainees who did not (P = .0097)., Conclusions: These data suggest the need for biannual refresher training in the management of acute contrast reactions to maintain trainees' knowledge and confidence., (Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.)
- Published
- 2012
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21. Hyperglycemia in hospitalized patients receiving corticosteroid premedication before the administration of radiologic contrast medium.
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Davenport MS, Cohan RH, Khalatbari S, Myles J, Caoili EM, and Ellis JH
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- Adolescent, Adult, Aged, Aged, 80 and over, Comorbidity, Female, Humans, Incidence, Male, Middle Aged, North Carolina epidemiology, Risk Assessment, Risk Factors, Young Adult, Adrenal Cortex Hormones administration & dosage, Contrast Media administration & dosage, Diabetes Mellitus epidemiology, Drug-Related Side Effects and Adverse Reactions epidemiology, Hospitalization statistics & numerical data, Hyperglycemia epidemiology, Premedication statistics & numerical data
- Abstract
Rationale and Objectives: To assess the effect of short-term corticosteroid premedication on serum glucose in hospitalized patients., Materials and Methods: Serum glucose in adult inpatients receiving corticosteroid premedication before a radiology study was compared to serum glucose in nonpremedicated controls between May 1, 2008, and September 12, 2009. Patients were categorized by type of nonionic contrast medium (intravenous [IV] or none) and route of corticosteroid premedication (oral, IV, none). Diabetes mellitus (types I and II) was evaluated as an independent risk factor. Patients without glucose estimations before and after premedication were excluded. Results were analyzed with analysis of variance and a stepwise linear regression analysis., Results: There were 390 corticosteroid premedication episodes in 390 patients; 873 examinations in 844 patients served as controls. Cohorts receiving corticosteroid premedication experienced a brief (24-48 hour) increase in mean maximum postbaseline serum glucose (IV, +81 mg/dL; oral, +70 mg/dL) that was greater than the increase in nonpremedicated controls (+46 mg/dL). Type I (+144 mg/dL) and type II (+108 mg/dL) diabetics had a greater elevation than nondiabetics (+34 mg/dL). Both corticosteroid premedication (IV, P = .02; oral, P = .01) and diabetes mellitus (type I, P = .0002; type II, P < .0001) were significant independent risk factors of hyperglycemia. The use of nonionic intravascular contrast medium was not (P = .7). There was no significant difference between IV and oral premedication (P = .6), or type I and type II diabetes mellitus (P = .8)., Conclusions: Diabetes mellitus (type I and type II) and corticosteroid premedication (oral and IV) are significant independent risk factors for the development of brief hyperglycemia near the time of inpatient radiology studies., (Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.)
- Published
- 2011
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22. CT appearances following laparoscopic partial nephrectomy for renal cell carcinoma using a rolled cellulose bolster.
- Author
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Pai D, Willatt JM, Korobkin M, Cohan RH, Ellis JH, Francis IR, Wolf JS, and Schipper M
- Subjects
- Carcinoma, Renal Cell pathology, Humans, Kidney Neoplasms pathology, Retrospective Studies, Carcinoma, Renal Cell diagnostic imaging, Carcinoma, Renal Cell surgery, Cellulose therapeutic use, Hemostasis, Surgical instrumentation, Kidney Neoplasms diagnostic imaging, Kidney Neoplasms surgery, Laparoscopy, Nephrectomy methods, Tomography, X-Ray Computed methods
- Abstract
Purpose: To describe the evolving computed tomography (CT) appearances of a cellulose surgical bolster used as a hemostatic agent in patients who undergo laparoscopic partial nephrectomy for renal cell carcinoma., Materials and Methods: We retrospectively reviewed the follow-up CT studies of 33 patients with stage T1N0M0 renal carcinoma who underwent laparoscopic partial nephrectomy using a rolled, oxidized, regenerated cellulose sheet sutured in place as a bolster in the parenchymal defect. Thirteen patients undergoing laparoscopic partial nephrectomy without the use of a bolster were also evaluated to differentiate imaging features., Results: The bolster-related masses were significantly larger than those seen in the non-bolster patients. There was a decrease in size of the post-operative bolster-related mass with time. The bolster shape evolved with time, initially appearing oval, and becoming irregular with decreasing size. Equivocal increase in attenuation of 10-20 HU was seen in 6 patients. Increase in attenuation of greater than 20 HU was seen in 3 patients. There was no evidence of tumor recurrence in any of the patients. Invagination of fat was seen in two bolster-related masses at 18 months or greater., Conclusions: Cellulose bolster has a variable appearance on follow-up CT exams. Evolutionary features include reduction in bolster size and shape with time leading finally to non-visualization. Bolster enhancement can mimic abscesses and tumor recurrence.
- Published
- 2010
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23. Retroperitoneal sarcomas.
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Francis IR, Cohan RH, Varma DG, and Sondak VK
- Subjects
- Humans, Magnetic Resonance Imaging, Neoplasm Staging, Positron-Emission Tomography, Prognosis, Retroperitoneal Neoplasms surgery, Sarcoma surgery, Tomography, X-Ray Computed, Diagnostic Imaging, Retroperitoneal Neoplasms diagnosis, Sarcoma diagnosis
- Abstract
Retroperitoneal sarcomas are rare neoplasms. CT or MR imaging is performed in patients with these tumors to detect local extent and distant metastases of the tumor and for preoperative surgical planning. Most sarcomas cannot be characterized as to cell type with CT or MR, with the exceptions being liposarcomas and intracaval leiomyosarcomas. Similarly histological grading cannot be made definitively with imaging alone, the exception being liposarcoma since well differentiated liposarcomas contain more macroscopic fat than do less differentiated liposarcomas. After surgery, follow up imaging with CT or MR and careful scrutiny of the tumor bed and resection site are essential to detect early recurrences, which can often be managed with re-resection., (Copyright International Cancer Imaging Society.)
- Published
- 2005
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24. Does medical school performance predict radiology resident performance?
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Boyse TD, Patterson SK, Cohan RH, Korobkin M, Fitzgerald JT, Oh MS, Gross BH, and Quint DJ
- Subjects
- Educational Measurement, Humans, Specialty Boards, United States, Internship and Residency, Radiology education, Schools, Medical
- Abstract
Rationale and Objectives: The authors performed this study to examine the relationship, if any, of a large number of measures of medical school performance with radiology residency performance., Materials and Methods: Applications of 77 radiology residents enrolled from 1991 to 2000 were reviewed. Medical school grades, dean's letter summary statements, letters of recommendation, selection to Alpha Omega Alpha (AOA), and National Board of Medical Examiners (NBME) and U.S. Medical Licensing Examination (USMLE) Step 1 scores were recorded. Student t tests, analysis of variance, and correlation coefficients were used to examine the relationship between these measures of medical school performance and subsequent performance during radiology residency as determined by rotation evaluations, retrospective faculty recall scores, and American College of Radiology (ACR) and American Board of Radiology (ABR) examination scores. Resident performance was also correlated with prestige of the medical school attended., Results: Preclinical grades of Honors or A; clinical grades of Honors or A in medicine, surgery, and pediatrics; and high NBME/USMLE scores strongly predicted success on the ABR written clinical examination but did not predict rotation performance. Most other measures of medical school performance, including outstanding Dean's letters and letters of recommendation, AOA selection during the senior year, and high medical school prestige did not predict high examination scores or superior rotation performance during residency., Conclusion: Success on the ABR examination can be predicted by medical school success in preclinical courses, some clinical courses, and USMLE examination scores. Dean's letters, letters of recommendation, AOA selection during the senior year, and medical school prestige do not appear to predict future resident performance as reliably.
- Published
- 2002
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25. Is past academic productivity predictive of radiology resident academic productivity?
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Patterson SK, Fitzgerald JT, Boyse TD, and Cohan RH
- Subjects
- Career Choice, Education, Medical, Undergraduate, Educational Measurement, Humans, Internship and Residency, Retrospective Studies, Achievement, Publishing statistics & numerical data, Radiology education
- Abstract
Rationale and Objectives: The authors performed this study to determine whether academic productivity in college and medical school is predictive of the number of publications produced during radiology residency., Materials and Methods: The authors reviewed the records of 73 radiology residents who completed their residency from 1990 to 2000. Academic productivity during college, medical school, and radiology residency, other postgraduate degrees, and past careers other than radiology were tabulated. The personal essay attached to the residency application was reviewed for any stated academic interest. Residents were classified as being either previously productive or previously unproductive. Publication rates during residency and immediately after residency were compared for the two groups. For the productive residents, a correlation analysis was used to examine the relationship between past frequency of publication and type of previous activity. Least-squares regression analysis was used to investigate the relationship between preresidency academic productivity, advanced degrees, stated interest in academics, and other careers and radiology residency publications., Results: There was no statistically significant difference in the number of articles published by those residents who were active and those who were not active before residency (P = .21). Only authorship of papers as an undergraduate was weakly predictive of residency publication., Conclusion: These selected measures of academic productivity as an undergraduate and during medical school are not helpful for predicting publication during residency. There was no difference in publication potential between those residents who were academically productive in the past and those who were not.
- Published
- 2002
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26. Effectiveness of abdominal compression during helical renal CT.
- Author
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Caoili EM, Cohan RH, Korobkin M, Platt JF, Francis IR, Gebremariam A, and Ellis JH
- Subjects
- Abdomen, Adolescent, Adult, Aged, Aged, 80 and over, Artifacts, Female, Humans, Male, Middle Aged, Pressure, Time Factors, Kidney Diseases diagnostic imaging, Kidney Tubules, Collecting diagnostic imaging, Tomography, X-Ray Computed methods, Ureter diagnostic imaging
- Abstract
Rationale and Objectives: The authors performed this study to assess the effect of abdominal compression on opacification and distention of the proximal renal collecting system during helical computed tomography (CT)., Materials and Methods: Abdominal compression was applied during helical CT in 31 patients who were scanned 150 and 300 seconds after initiating a dynamic bolus injection of contrast material. Two reviewers assessed renal collecting system opacification and measured the maximal short-axis diameter of the collecting system at three locations: the upper pole, the lower pole, and the proximal ureter. A similar evaluation was performed in a control group of 29 patients who underwent CT without compression at 300 seconds after initiating the injection of contrast material., Results: Both reviewers noted collecting system opacification at all locations in 52 of 56 noncompressed collecting systems scanned at 300 seconds, 57 of 59 compressed collecting systems scanned at 300 seconds, but only 26 of 59 compressed collecting systems scanned at 150 seconds. Measured collecting system distention was statistically significantly greater at 300 seconds in patents who received compression than in patients who did not (P = .0013). For patients who received compression, measured collecting system distention was statistically significantly greater on scans obtained at 300 seconds than on scans obtained at 150 seconds (P = .0001)., Conclusion: Abdominal compression during renal helical CT produces a detectable increase in renal collecting system distention. In patients who receive compression, scanning at 300 seconds rather than at 150 seconds results in greater collecting system distention and more consistent opacification.
- Published
- 2001
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27. Correlation between radiology resident rotation performance and examination scores.
- Author
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Adusumilli S, Cohan RH, Korobkin M, Fitzgerald JT, and Oh MS
- Subjects
- Analysis of Variance, Humans, Societies, Medical, United States, Educational Measurement methods, Internship and Residency, Radiology education, Specialty Boards
- Abstract
Rationale and Objectives: The authors' purpose was to determine whether there is a relationship between subjective assessment of radiology resident performance on individual rotations and objective assessment of radiology resident performance on the American College of Radiology (ACR) in-training and American Board of Radiology (ABR) written examinations., Materials and Methods: Records of 81 radiology residents completing their residency between 1991 and 2000 were reviewed. Mean scores from all rotation evaluation forms obtained during the study period were calculated for each residency year. The means of the overall raw scores and percentiles obtained on the annual ACR in-training examinations during the first 3 years of residency and of the written portion of the ABR examination taken during the 4th year of residency were also determined. Rotation evaluation scores were then compared to examination scores obtained during the same year of residency, and correlation coefficients were obtained., Results: In the 2nd, 3rd, and 4th years of radiology residency, there is positive correlation between rotation evaluation scores and overall scores from the corresponding ACR in-training examination and written portion of the ABR examination taken during the same year. In contrast, in the 1st year of residency, resident rotation evaluation scores do not correlate with ACR in-training examination scores., Conclusion: Residents who are perceived as doing well on their rotations after the 1st year of residency are more likely to do well on standardized written examinations.
- Published
- 2000
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28. How well does applicant rank order predict subsequent performance during radiology residency?
- Author
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Adusumilli S, Cohan RH, Marshall KW, Fitzgerald JT, Oh MS, Gross BH, and Ellis JH
- Subjects
- Forecasting, United States, Internship and Residency, Radiology education, School Admission Criteria
- Abstract
Rationale and Objectives: Residency selection committees expend substantial time and resources on assessing the quality of residency applicants to derive an appropriate rank order for the National Residency Matching Program. The authors determined whether there is a relationship between the rank number or rank percentile of applicants selected for a residency training program and subsequent radiology residency performance., Materials and Methods: Records of radiology residents completing their residency between 1991 and 1998 were reviewed. Available rank numbers and rank percentiles for each resident were compared with subsequent performance, as assessed subjectively by 4th-year radiology rotation evaluation forms and retrospective recall of four senior faculty members and objectively by numerical and percentile scores on the written portion of the American Board of Radiology (ABR) examinations. Correlation coefficients were obtained for each comparison., Results: Rank number and rank percentile were not significantly correlated with 4th-year resident rotation evaluations or ABR written examination scores or percentiles. A small correlation existed between rank order and retrospective evaluation of resident performance by the four senior faculty., Conclusion: Applicant rank number and rank percentile do not correlate with subsequent radiology residency performance as assessed on rotation evaluation forms or the ABR written examinations.
- Published
- 2000
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29. Utility of routine trauma CT in the detection of bladder rupture.
- Author
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Pao DM, Ellis JH, Cohan RH, and Korobkin M
- Subjects
- Adolescent, Adult, Aged, Child, Child, Preschool, Female, Fractures, Bone diagnostic imaging, Humans, Infant, Male, Middle Aged, Pelvis diagnostic imaging, Pelvis injuries, Retrospective Studies, Rupture, Urinary Bladder diagnostic imaging, Urography methods, Abdominal Injuries diagnostic imaging, Tomography, X-Ray Computed statistics & numerical data, Urinary Bladder injuries, Wounds, Nonpenetrating diagnostic imaging
- Abstract
Rationale and Objectives: The purpose of this study was to determine the frequency with which routine computed tomography (CT) fails to depict bladder rupture, the potential utility of delayed CT scans, and whether these findings might be useful in determining which patients may require subsequent cystography., Materials and Methods: Cystograms and abdominal and pelvic CT scans of 54 patients with blunt trauma and in whom bladder rupture was clinically suspected were retrospectively reviewed. Blind readings of CT scans were performed by two genitourinary radiologists. Cystograms were used as the standard., Results: Cystograms depicted bladder rupture in 10 patients. On CT scans, extravesical fluid was depicted in all three patients with intraperitoneal bladder rupture (although only a small amount of pelvic intraperitoneal fluid was present in two of these patients), in all seven patients with extraperitoneal bladder rupture, and in 32 of the 44 patients without bladder injury. Contrast material had been excreted into the bladder at the time of the initial or delayed CT in eight patients with bladder rupture; however, extravasation was identified in only four of the eight. In two of the four patients without extravasation, the bladder was distended at the time of CT. No bladder injuries were found in the 12 patients in whom pelvic fluid was not identified on CT scans., Conclusion: The absence of pelvic fluid on a trauma CT scan indicates that bladder rupture is unlikely. Even when a partially opacified bladder is passively distended, bladder injury may be present despite the absence of contrast material extravasation.
- Published
- 2000
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30. Occurrence of adverse reactions to gadolinium-based contrast material and management of patients at increased risk: a survey of the American Society of Neuroradiology Fellowship Directors.
- Author
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Murphy KP, Szopinski KT, Cohan RH, Mermillod B, and Ellis JH
- Subjects
- Data Collection, Drug Hypersensitivity etiology, Drug Hypersensitivity prevention & control, Drug Hypersensitivity therapy, Gadolinium DTPA adverse effects, Heterocyclic Compounds adverse effects, Humans, Organometallic Compounds adverse effects, Risk Factors, Contrast Media adverse effects, Gadolinium adverse effects, Magnetic Resonance Imaging
- Abstract
Rationale and Objectives: The authors attempted to determine the frequency and severity of adverse reactions to gadolinium-based magnetic resonance (MR) contrast agents and to identify strategies for management of patients at increased risk., Materials and Methods: American Society of Neuroradiology program directors were surveyed about adverse reactions at their institutions to gadolinium-based contrast agents, the contrast agents responsible, and the management of patients with allergy-like reactions to iodinated or gadolinium-based agents who required MR contrast agent administration., Results: Fifty-three (50.5%) surveys were received from 105 centers. Of 687,255 gadopentetate dimeglumine injections, 314 (0.046%) nonallergic reactions and 107 (0.016%) mild, 28 (0.004%) moderate, and five (0.001%) severe allergy-like reactions occurred. Of 74,275 gadodiamide injections, 11 (0.015%) nonallergic and 12 (0.016%) mild allergy-like reactions occurred. Of 64,005 gadoteridol administrations, 171 (0.267%) nonallergic reactions and 49 (0.077%) mild, 29 (0.047%) moderate, and 11 (0.017%) severe allergy-like reactions occurred. Twenty-six departments took no precautions for patients with previous allergy-like reactions to iodinated contrast material. Nineteen did not premedicate patients who previously had reactions to gadolinium-based agents before repeat administration of MR contrast agents., Conclusion: Although MR contrast agents are safe, adverse reactions occur. Many centers have not adopted policies for the OFF
- Published
- 1999
- Full Text
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31. Local reactions after injection of iodinated contrast material: detection, management, and outcome.
- Author
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Cohan RH, Bullard MA, Ellis JH, Jan SC, Francis IR, Garner WL, and Dunnick NR
- Subjects
- Blister chemically induced, Catheterization instrumentation, Diatrizoate adverse effects, Diatrizoate Meglumine adverse effects, Equipment Design, Extravasation of Diagnostic and Therapeutic Materials diagnosis, Extravasation of Diagnostic and Therapeutic Materials therapy, Follow-Up Studies, Humans, Injections, Intravenous adverse effects, Injections, Intravenous instrumentation, Iohexol adverse effects, Ions, Irritants adverse effects, Pain chemically induced, Phlebography, Risk Factors, Tomography, X-Ray Computed, Treatment Outcome, Urography, Contrast Media adverse effects, Extravasation of Diagnostic and Therapeutic Materials etiology, Iodine adverse effects
- Abstract
Rationale and Objectives: The authors assessed the frequency, sequelae, and risk factors of extravasation of intravenously administered iodinated contrast media., Materials and Methods: All patients with local reactions after intravenous injection of contrast media between November 1994 and December 1996 were studied. Comparison was made with data obtained from a control group of 100 patients with no local reactions who underwent contrast material-enhanced computed tomography (CT)., Results: Local reactions were reported in 56 (0.25%) of 22,254 patients who received intravenous injections of iodinated contrast media. Fifty-one patients experienced extravasation, and five patients experienced local irritation in the absence of clinically detectable extravasation. Extravasation occurred during CT (n = 46), urography (n = 4), and venography (n = 1). Contrast material was nonionic in 37 cases and conventional ionic in 14 cases of extravasation. Extravasated volumes exceeded 30 mL in 22 patients and 100 mL in six patients. Forty-five (80%) of 56 patients with local reactions had complete resolution of symptoms within 24 hours. Only four patients had symptoms for more than 48 hours. No surgery was required. Compared with the control group, patients with extravasation were significantly more likely to have been injected with small-bore catheters (21 or 22 gauge) and to have been injected at low or high rates., Conclusion: Symptoms of contrast medium extravasation usually resolve quickly. In patients with extravasation, injections are more likely to have been performed with techniques that vary from normal practice.
- Published
- 1997
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32. Cystic renal masses: a reevaluation of the usefulness of the Bosniak classification system.
- Author
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Wilson TE, Doelle EA, Cohan RH, Wojno K, and Korobkin M
- Subjects
- Adenocarcinoma pathology, Adolescent, Adult, Aged, Carcinoma, Renal Cell pathology, Female, Humans, Kidney Diseases, Cystic pathology, Kidney Neoplasms pathology, Male, Middle Aged, Radiographic Image Enhancement, Retrospective Studies, Adenocarcinoma diagnostic imaging, Carcinoma, Renal Cell diagnostic imaging, Kidney Diseases, Cystic classification, Kidney Diseases, Cystic diagnostic imaging, Kidney Neoplasms diagnostic imaging, Tomography, X-Ray Computed
- Abstract
Rationale and Objectives: We evaluated the utility of the Bosniak system for classifying cystic renal masses on computed tomography (CT) scans., Methods: The CT scans of 20 patients with 24 cystic renal masses that were subsequently surgically removed or biopsied were reviewed retrospectively. Masses were categorized using the Bosniak system and were correlated with the pathology results., Results: The final pathology results of the cystic renal masses were as follows: Seven of seven category I lesions were benign, one of five category II lesions was benign, zero of four category III lesions were benign, and zero of six category IV lesions were benign. Neither of two unclassifiable cystic lesions were benign. The average enhancement of lesions in categories II, III, and IV was 6.3, 2.3, and 27.6 Hounsfield units (H), respectively. The two uncategorizable lesions had a mean enhancement of 26.8 H., Conclusion: The results of our study serve to underscore some limitations of the Bosniak classification system because most of our category II and all of our category III lesions were malignant, suggesting that minimally complex cystic renal masses may contain malignant cells. Contrast enhancement of less than 10 H was demonstrated in lesions in categories II and III.
- Published
- 1996
- Full Text
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33. Improvement of faculty teaching performance: efficacy of resident evaluations.
- Author
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Cohan RH, Dunnick NR, Blane CE, and Fitzgerald JT
- Subjects
- Faculty, Medical, Forms and Records Control, Humans, Internship and Residency, Radiology education, Teaching
- Abstract
Rationale and Objectives: We assessed the effects on the perceived quality of faculty teaching of a resident evaluation form that solicits specific comments on faculty strengths and weaknesses., Methods: An evaluation form was devised that rated faculty on a scale of 1-10 in teaching conference quality, availability, efficiency, and teaching. The form requested constructive comments on faculty strengths and weaknesses. The forms were completed anonymously by residents at all levels. Individual results and means for the department were tabulated and provided to each faculty member in a personal interview. Change in performance was assessed by comparing faculty evaluation scores for 2 consecutive years., Results: The mean faculty scores for teaching conference quality, availability, efficiency, and teaching increased from 7.8, 7.9, 7.9, and 7.7 to 8.1, 8.3, 8.3, and 8.1 in each of the respective areas. The scores of the faculty members who initially received the 10 lowest scores rose to an even greater extent (from 6.2, 6.2, 6.0, and 6.0 to 6.8, 7.4, 7.3, and 6.8 in each of the respective areas), whereas the scores of the faculty members who initially received the 10 highest scores remained relatively constant., Conclusion: The perceived quality of certain focused aspects of resident teaching can be modified by use of resident evaluations that solicit specific suggestions for improvement. With appropriate feedback, this is an effective tool for improving the teaching performance of radiology department faculty, particularly those considered to be the weakest teachers.
- Published
- 1996
- Full Text
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34. Total central vein obstruction: resolution with angioplasty and fibrinolysis.
- Author
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Newman GE, Saeed M, Himmelstein S, Cohan RH, and Schwab SJ
- Subjects
- Adult, Constriction, Pathologic, Female, Fibrinolysis, Humans, Male, Middle Aged, Veins drug effects, Veins surgery, Angioplasty, Balloon, Arteriovenous Shunt, Surgical adverse effects, Renal Dialysis adverse effects, Veins pathology
- Published
- 1991
- Full Text
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35. Non-seminomatous testicular tumors: effect of lesion side on CT detection of lymph node metastasis.
- Author
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Munechika H, Cohan RH, and Dunnick NR
- Subjects
- Adolescent, Adult, Aged, Child, False Negative Reactions, Humans, Lymphatic Metastasis, Male, Middle Aged, Reproducibility of Results, Retroperitoneal Space, Retrospective Studies, Rhabdomyosarcoma pathology, Teratoma pathology, Testicular Neoplasms pathology, Rhabdomyosarcoma diagnostic imaging, Teratoma diagnostic imaging, Testicular Neoplasms diagnostic imaging, Tomography, X-Ray Computed
- Abstract
Abdominal CT examinations of 40 patients with non-seminomatous testicular tumors were reviewed with previous knowledge of the side of the testicular primary. Metastatic nodes, between 1.5 cm and 2.0 cm in diameter were overlooked more frequently in patients with right than in those with left testicular primaries, because mildly enlarged aorto-caval or para-caval nodes (which are the most frequent site of metastasis from a right testicular lesion) were more difficult to detect than enlarged left para-aortic lymph nodes. Efforts to delineate the aorto-caval region on CT examinations of patients with right-sided lesions must be increased in order to reduce a surprisingly high false negative rate.
- Published
- 1988
- Full Text
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36. Hemodialysis-associated subclavian vein stenosis.
- Author
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Schwab SJ, Quarles LD, Middleton JP, Cohan RH, Saeed M, and Dennis VW
- Subjects
- Angioplasty, Balloon, Constriction, Pathologic etiology, Constriction, Pathologic therapy, Female, Humans, Male, Middle Aged, Radiography, Arteriovenous Shunt, Surgical, Catheterization, Central Venous adverse effects, Renal Dialysis, Subclavian Vein diagnostic imaging
- Abstract
This study was undertaken to evaluate hemodialysis-associated subclavian vein stenosis (SVS) and to clarify treatment of this condition. Forty-seven patients underwent upper arm venography to evaluate fistula dysfunction. Subclavian vein stenosis was documented in 12. Eleven of 12 had elevated venous dialysis pressure (196 +/- 8.9 mm Hg), and six had arm edema. All 12 had previously undergone subclavian cannulation on the side of the fistula. Thirty-five patients showed no evidence of subclavian vein stenosis. Twelve of these 35 patients (mean venous dialysis pressure 113 +/- 2.3 mm Hg) had undergone previous subclavian cannulation on the side of the fistula. The mean age of the fistula at the time of venogram in patients with subclavian vein stenosis was 17.0 months versus 5.8 months in patients with ipsilateral subclavian cannulation without subclavian vein stenosis. Percutaneous transluminal angioplasty (PTA) was performed on 11 of 12 patients with SVS lowering venous dialysis pressure and restoring patency to the fistula in 100%. Lesions recurred in two of 11 patients and were successfully retreated with PTA. We conclude that SVS is a common dialysis problem that is amenable to treatment with PTA. Elevated venous dialysis pressures are a sensitive indicator of this condition.
- Published
- 1988
- Full Text
- View/download PDF
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