ABSTRACT
BACKGROUND: Objective structured clinical examinations (OSCEs) are a useful method to evaluate medical students' performance in the clerkship years. OSCEs are designed to assess skills and knowledge in a standardized clinical setting and through use of a preset standard grading sheet, so that clinical knowledge can be evaluated at a high level and in a reproducible way. OBJECTIVE: This study aimed to present our OSCE assessment tool designed specifically for radiology clerkship medical students, which we called the objective structured radiology examination (OSRE), with the intent to advance the assessment of clerkship medical students by providing an objective, structured, reproducible, and low-cost method to evaluate medical students' radiology knowledge and the reproducibility of this assessment tool. METHODS: We designed 9 different OSRE cases for radiology clerkship classes with participating third- and fourth-year medical students. Each examination comprises 1 to 3 images, a clinical scenario, and structured questions, along with a standardized scoring sheet that allows for an objective and low-cost assessment. Each medical student completed 3 of 9 random examination cases during their rotation. To evaluate for reproducibility of our scoring sheet assessment tool, we used 5 examiners to grade the same students. Reproducibility for each case and consistency for each grader were assessed with a two-way mixed effects intraclass correlation coefficient (ICC). An ICC below 0.4 was deemed poor to fair, an ICC of 0.41 to 0.60 was moderate, an ICC of 0.6 to 0.8 was substantial, and an ICC greater than 0.8 was almost perfect. We also assessed the correlation of scores and the students' clinical experience with a linear regression model and compared mean grades between third- and fourth-year students. RESULTS: A total of 181 students (156 third- and 25 fourth-year students) were included in the study for a full academic year. Moreover, 6 of 9 cases demonstrated average ICCs more than 0.6 (substantial correlation), and the average ICCs ranged from 0.36 to 0.80 (P<.001 for all the cases). The average ICC for each grader was more than 0.60 (substantial correlation). The average grade among the third-year students was 11.9 (SD 4.9), compared with 12.8 (SD 5) among the fourth-year students (P=.005). There was no correlation between clinical experience and OSRE grade (-0.02; P=.48), adjusting for the medical school year. CONCLUSIONS: Our OSRE is a reproducible assessment tool with most of our OSRE cases showing substantial correlation, except for 3 cases. No expertise in radiology is needed to grade these examinations using our scoring sheet. There was no correlation between scores and the clinical experience of the medical students tested.
ABSTRACT
PURPOSE: To evaluate the image quality and clinical utility of a polytrauma computed tomographic (CT) protocol that integrates lower extremity CT angiography into multiphasic whole-body trauma CT by utilizing 64-detector CT and a single contrast material bolus. MATERIALS AND METHODS: This retrospective study was institutional review board approved and HIPAA compliant. Informed consent was waived. All patients who underwent CT angiography of the lower extremities integrated with multiphasic torso CT for trauma between May 2005 and September 2009 were included. Two hundred eighty-four patients met the inclusion criteria. The mechanism of trauma was blunt injury in 228 (80.3%) of 284 patients and penetrating in 56 (19.7%) of 284 patients. CT angiography encompassed the joints proximal and distal to the injured region, with scan delay fixed at 25 seconds. Two radiologists retrospectively reviewed all the extremity CT angiograms, noting the presence of vascular injury, and measured the attenuation in the lower extremity arteries. Arterial attenuation, in Hounsfield units, was measured at multiple vascular divisions, and CT angiographic results were compared with clinical outcome, and if available, repeat lower extremity CT angiographic, conventional angiographic, or surgical findings. Sensitivity and specificity with 95% confidence intervals were calculated. RESULTS: Sixty-three arterial injuries were identified in 44 (15.5%) of 284 patients as follows: occlusion (n = 37), narrowing (n = 9), active extravasation (n = 14), pseudoaneurysm (n= 2), and arteriovenous fistula (n = 1). Three patients underwent conventional angiography after CT angiography. Seven patients underwent surgical therapy with all CT angiographic findings confirmed. There were no injuries subsequently identified in the subgroup with a negative result at CT angiography. Of the 864 vascular divisions in which attenuation was measured, 69 (8%) of 864 had a mean attenuation less than 150 HU. CONCLUSION: Integration of lower extremity CT angiography into multiphasic whole-body trauma imaging is feasible, helps detect clinically relevant vascular injuries, and results in diagnostic image quality in the majority of patients.
