Resident Interpretation of Emergency CT Scans in the Evaluation of Acute Appendicitis

PURPOSE: Radiology resident interpretation of computed tomographic (CT) scans at academic institutions often guides management of cases of suspected acute appendicitis in the emergency department. The purpose of this study was to compare resident and faculty interpretation of CT scans obtained for acute appendicitis. MATERIALS AND METHODS: From December 16, 1999, to July 13, 2000, CT was performed in 103 consecutive patients between the hours of 9:00 PM and 8:00 AM who were suspected of having acute appendicitis. The authors compared the residents' preliminary written interpretations with both the final reports written by the faculty and the surgical findings. The faculty interpreting the CT scans were aware of resident interpretations but were not aware that a study was being conducted. RESULTS: The final faculty interpretation and the preliminary resident interpretation were identical in 96 of the 103 patients (93%; 95% confidence interval: 87.8%, 97.2%). In only one patient was a scan originally interpreted as negative interpreted as positive by the faculty member. Clinically, the patient did not have acute appendicitis, and surgery was not perforrmed. CONCLUSION: In the diagnosis of acute appendicitis, image interpretations made by adequately trained radiology residents can be expected to closely match those of the radiology faculty, and the practice of after-hours interpretation of such studies by radiology residents is safe.     

Radiology resident evaluation of head CT scan orders in the emergency department

BACKGROUND AND PURPOSE: Prior studies have revealed little difference in residents' abilities to interpret cranial CT scans. The purpose of this study was to assess the performance of radiology residents at different levels of training in the interpretation of emergency head CT images. METHODS: Radiology residents prospectively interpreted 1324 consecutive head CT scans ordered in the emergency department at the University of Arizona Health Science Center. The residents completed a preliminary interpretation form that included their interpretation and confidence in that interpretation. One of five neuroradiologists with a Certificate of Added Qualification subsequently interpreted the images and classified their assessment of the residents' interpretations as follows: "agree," "disagree-insignificant," or "disagree-significant." The data were analyzed by using analysis-of-variance or chi-squared methods. RESULTS: Overall, the agreement rate was 91%; the insignificant disagreement rate, 7%; and the significant disagreement rate, 2%. The level of training had a significant (P =.032) effect on the rate of agreement; upper-level residents had higher rates of agreement than those of more junior residents. There were 62 false-negative findings. The most commonly missed findings were fractures (n = 18) and chronic ischemic foci (n = 12). The most common false-positive interpretations involved 10 suspected intracranial hemorrhages and suspected fractures. CONCLUSION: The level of resident training has a significant effect on the rate of disagreement between the preliminary interpretations of emergency cranial CT scans by residents and the final interpretations by neuroradiologists. Efforts to reduce residents' errors should focus on the identification of fractures and signs of chronic ischemic change.     

Suspected acute appendicitis: nonenhanced helical CT in 300 consecutive patients.

PURPOSE: To determine the accuracy of helical computed tomography (CT) without the oral, intravenous, or rectal administration of contrast material in confirming suspected acute appendicitis. MATERIALS AND METHODS: Three hundred consecutive patients referred from the departments of surgery and emergency medicine were examined for suspected acute appendicitis by using thin-section nonenhanced helical CT. All transverse CT scans were obtained in a single breath hold from the upper abdomen (T12 vertebra) to the pubic symphysis with 5-mm collimation and a pitch of 1.6. All scans were obtained without oral, intravenous, or rectal contrast material. Criteria for diagnosis of acute appendicitis included an enlarged appendix (> 6 mm) and periappendiceal inflammation. CT diagnoses were recorded prospectively. Final diagnoses were established with the results of surgical or clinical follow-up or both. RESULTS: There were 110 true-positive diagnoses, 181 true-negative diagnoses (63 of which were an alternative diagnosis correctly established prospectively), five false-negative diagnoses, and four false-positive diagnoses, which yielded a sensitivity of 96%, a specificity of 99%, and an accuracy of 97%. CONCLUSION: Nonenhanced helical CT is a highly accurate technique for diagnosing or excluding acute appendicitis. Developing experience with the technique and understanding the subtleties of interpretation can further improve diagnostic accuracy.     

Suspected appendicitis in children: diagnosis with contrast-enhanced versus nonenhanced Helical CT

PURPOSE: To compare the diagnostic accuracy of limited-area (lower abdominal) nonenhanced helical computed tomography (CT), intravenous contrast material-enhanced helical CT of the entire abdomen, and the combination of both. MATERIALS AND METHODS: Three hundred six children suspected of having appendicitis, who were previously included in a prospective study, underwent limited-area nonenhanced helical CT of the lower abdomen and contrast-enhanced CT of the entire abdomen. No oral or rectal contrast material was administered. The CT scans were retrospectively reviewed by three independent readers both separately and together. The readers were blinded to all clinical information and to the results of previous ultrasonographic and CT examinations. Final diagnoses were established on the basis of surgical, histopathologic, or clinical follow-up findings. The Pearson chi(2) test was performed to compare values between groups. The Student two-sample t test was performed to determine statistically significant differences in age and sex. RESULTS: One hundred twenty-nine patients (42%) had appendicitis. Readers diagnosed appendicitis with 66% pooled sensitivity and 96% pooled specificity with limited-area nonenhanced CT. With contrast-enhanced CT of the entire abdomen, appendicitis was diagnosed with 90% pooled sensitivity and 94% pooled specificity. With both sequences together, readers diagnosed appendicitis with 90% pooled sensitivity and 94% pooled specificity. The difference between the sensitivity of limited-area nonenhanced CT and that of contrast-enhanced CT was statistically significant (P <.001). CONCLUSION: Sensitivity of helical CT for suspected appendicitis in children improved significantly with abdominal contrast-enhanced CT compared with limited-area nonenhanced CT. No further improvement in sensitivity was achieved with the combination of both sequences in comparison to that with contrast-enhanced CT alone.     

Overnight resident preliminary interpretations on CT Examinations: should the process continue?

We report our experience with resident preliminary interpretations given at night on both abdominal and neurological CT scans to quantify the discrepancy rate when compared to the final report. An attempt was also made to document any adverse clinical outcomes as a result of the preliminary interpretation. From January 1, 2004 to December 31, 2004, adult CT examinations were prospectively interpreted by residents at night at a level I trauma center. Both the neurological and body CT scans were reviewed beginning at 7:00 a.m. the following morning by the respective subspecialty staff and discrepancies were noted. Adult CT examinations (6,858) were prospectively interpreted by residents: 5,206 cranial spinal CT examinations and 1,652 body CT examinations. Among the neurological studies, there were six cases identified as major discrepancies (0.1%) and 185 minor discrepancies (3.5%). Among the body CT cases, there were seven cases identified as major discrepancies (0.4%) and 23 cases of minor discrepancies (1.4%). There is a low discrepancy rate (0.2% major and 3.1% minor) in the preliminary resident interpretations from the final report. The process of overnight preliminary CT interpretations should continue as it is not substandard care.Presented at the American Society of Emergency Radiology 2005 Annual Meeting, Tucson, Arizona.     

The DePICTORS Study: discrepancies in preliminary interpretation of CT scans between on-call residents and staff

At many academic hospitals, radiology residents provide preliminary interpretations of CT studies performed outside of regular working hours. We examined the rate of discrepancies between resident interpretations and final reports issued by staff. We prospectively obtained 1,756 preliminary reports and corresponding final reports for computed tomography (CT) scans performed on call between November 2006 and March 2007. The overall rate of clinically significant discrepancies (those that would potentially alter the patient’s clinical course prior to issue of the final report) was 2.0%. Major discrepancy rates for abdominal/pelvic, chest, cervical spine and head CT were 4.1%, 2.5%, 1.0% and 0.7%, respectively. Senior residents had fewer major discrepancies compared to their junior colleagues. Time of interpretation was also evaluated, but a statistically significant relationship was not observed. In summary, this study demonstrates a low discrepancy rate between residents and staff radiologists and identifies areas where after-hours service may be further improved.     

Unenhanced limited CT of the abdomen in the diagnosis of appendicitis in children: comparison with sonography

OBJECTIVE. The purpose of this investigation is to determine the sensitivity, specificity, and accuracy of unenhanced limited CT of the abdomen in children with suspected appendicitis and compare these results with graded compression sonography. MATERIALS AND METHODS. Seventy-six children underwent unenhanced limited CT over a 11-month period for evaluation of suspected appendicitis. A historical cohort of 86 consecutive children who had undergone graded compression sonography was identified. Results were correlated with surgical, pathologic, chart, and clinical follow-up data. The sensitivity, specificity, accuracy, rate of alternate diagnosis, time to perform examinations, and charge at our institution were determined for unenhanced limited CT and sonography. RESULTS. Sensitivity, specificity, and accuracy for unenhanced limited CT were 97%, 100%, 99%, respectively, and were 100%, 88%, 91%, respectively, for sonography. Alternate diagnoses were suggested in 35% and 28% children without appendicitis who had unenhanced limited CT and sonography, respectively. Unenhanced limited CT required 5 min and sonography required 20-30 min to perform. The charge at our institution was $408 for unenhanced limited CT and $295 for sonography. CONCLUSIONS. CT can be performed rapidly in children without IV, oral, or rectal contrast medium. Unenhanced limited CT and sonography are highly sensitive, specific, and accurate in the evaluation of children with suspected appendicitis.     

Acute brain infarct: detection and delineation with CT angiographic source images versus nonenhanced CT scans

PURPOSE: To retrospectively compare sensitivity and specificity of admission nonenhanced computed tomographic (CT) scans with those of CT angiographic source images in detection of early ischemic changes in middle cerebral artery (MCA) stroke and to retrospectively compare admission nonenhanced CT scans with CT angiographic source images in delineation of final infarct extent, with follow-up images as reference. MATERIALS AND METHODS: Informed consent and institutional review board approval were received for this HIPAA-compliant study. Nonenhanced scans and angiographic source images obtained within 12 hours of symptom onset in 51 patients suspected of having MCA stroke were reviewed. Two blinded neuroimagers rated presence and extent of hypoattenuation on nonenhanced scans and angiographic source images with Alberta Stroke Programme Early CT Score (ASPECTS). Level of certainty for hypoattenuation detection was assigned a grade with a five-point scale. With receiver operating characteristic (ROC) curve analysis, nonenhanced scans and angiographic source images were compared for stroke detection. For stroke delineation, linear regression coefficients determined correlations of ASPECTS for nonenhanced scans and angiographic source images with ASPECTS for follow-up images. Multiple linear regressions were used to compare these correlations. RESULTS: Follow-up nonenhanced CT scans, diffusion-weighted magnetic resonance (MR) images, or fluid-attenuated inversion-recovery MR images were obtained (mean time to follow-up, 5.4 days); 33 patients had infarction. With level of certainty cutoff score of 4 or greater (probable, definite) for ischemic hypoattenuation, sensitivity for detection of acute stroke was 48% (nonenhanced scans) and 70% (angiographic source images) (P = .04, ROC analysis); specificity was 100% for both. Linear regression revealed R(2) = 0.42 (P < .001) for correlation between delineation of stroke on nonenhanced scans and on follow-up images evaluated with ASPECTS and 0.73 (P < .001) for correlation between delineation on angiographic source images and follow-up images evaluated with ASPECTS (P < .001, nonenhanced scans vs angiographic source images). CONCLUSION: CT angiographic source images, compared with nonenhanced CT scans, are more sensitive in detection of early irreversible ischemia and more accurate for prediction of final infarct volume.     

Resident interpretation of emergency computed tomographic scans

Our busy, urban emergency room is staffed by radiology residents after working hours. To determine the accuracy of our residents' interpretations of emergency cranial computed tomographic (CT) scans, the authors reviewed the preliminary reports of our residents for a two-month period. A total of 289 cranial CT scans were retrospectively reviewed and the resident interpretation judged acceptable, minor error, moderate error, or major error. Six of 289 neurologic examinations (2%) had moderate (4) or major (2) errors. The mistakes all involved misinterpretation of cerebral hemorrhage. The 98% accuracy in interpretation of cranial CT is higher than the accuracy reported with emergency plain film (PF) interpretation.     

Significant on-call misses by radiology residents interpreting computed tomographic studies: Perception versus cognition

The purpose of this study was to evaluate the etiology of significant false-negative computed tomographic (CT) interpretations by radiology residents on-call. Over a 1-year period, significant on-call false-negative CT interpretations were analyzed to determine whether errors were perceptual (i.e., the resident did not see the finding or findings) or cognitive (i.e., the resident did not recognize the implications or misinterpreted a finding or findings). Significant misses were defined as errors that delayed surgical treatment or misdirected management in a potentially life-threatening manner.A total of 12 significant false-negative interpretations occurred over a 1-year period. All head CT misses (extraaxial hemorrhage, pneumocephalus, contusion, subarachnoid hemorrhage due to ruptured aneurysm) were perceptual errors. Misses on thoracic, abdominal, and pelvic CT scans (2 abscesses, abdominal aortic aneurysm rupture, superior vena cava perforation due to catheter placement, ischemic bowel, liver laceration, hypoperfusion syndrome, appendicitis) were mixed (4 cognitive and 4 perceptual errors).Since the diagnostic possibilities of emergency head CT scans are limited, residents missed only subtle, perceptual manifestations and had little difficulty interpreting findings when they were correctly recognized. The gamut of diagnostic possibilities in the thorax, abdomen, and pelvis was more challenging to residents on-call; errors in both perception and interpretation arose with equal frequency, and the significant error rate was higher than that for head CT interpretation. Junior residents, who make most of the significant on-call errors, commonly feel overwhelmed in attempting to assimilate the knowledge required to take call. Prepartion needs to be extensive, yet it should be focused on areas that will engender optimal impact on after-hours performance. When preparing residents to interpret on-call CT studies, perceptual manifestations of neuroradiology should be emphasized, whereas a more comprehensive approach to thoracic, abdominal, and pelvic disorders needs to be stressed.Presented at the 8th Annual Meeting of the American Society of Emergency Radiology, New Orleans, March 20, 1997     

Conventional and hydrocolonic US of the appendix with CT correlation performed by on-call radiology residents

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the feasibility and accuracy of emergent hydrocolonic ultrasonography (US) performed by on-call residents in patients suspected of having appendicitis. MATERIALS AND METHODS: Thirty-one patients with a clinically equivocal diagnosis of appendicitis were prospectively evaluated with conventional US, hydrocolonic US, and appendiceal computed tomography (CT). Midlevel radiology residents performed the US examinations while they were on call. Sensitivity, specificity, and accuracy for diagnosing appendicitis were calculated for conventional and hydrocolonic US by using clinical outcome as the standard. Results of US and CT of the appendix were also correlated. Residents recorded their diagnostic confidence for conventional and hydrocolonic US. All patients were able to hold the rectally administered contrast material until completion of both hydrocolonic US and appendiceal CT. RESULTS: The sensitivity for detecting appendicitis with conventional US, hydrocolonic US, and appendiceal CT was 50%, 75%, and 100%, respectively. Specificity was 96%, 93%, and 93%, respectively. Identification of the normal and abnormal appendix improved from 13% (four of 31 patients) with conventional US to 35% (11 of 31 patients) with hydrocolonic US. The radiology residents' diagnostic confidence increased from 0.74 with conventional US to 0.83 with hydrocolonic US. CONCLUSION: Hydrocolonic US is a feasible addition to conventional US examination for patients suspected of having appendicitis. It improves sensitivity, increases radiology residents' confidence, and is well tolerated by patients.     

Radiology resident interpretations of on-call imaging studies: the incidence of major discrepancies

RATIONALE AND OBJECTIVES: To determine the incidence of radiology resident preliminary interpretation errors for plain film, body computed tomography, and neuroradiology (neuro)computed tomographic examinations read on call. MATERIALS AND METHODS: We retrospectively reviewed the data in a prospectively acquired resident quality assurance (QA) database dating between January 2000 and March 2007. The database comprises all imaging studies initially interpreted by an on-call resident and later reviewed by a board-certified attending radiologist who determined the level of discrepancy between the two interpretations according to a graded scale from 0 (no discrepancy) to 3 (major discrepancy). We reviewed the data with respect to resident training level, imaging modality, and variance level. Statistical analysis was performed with chi(2) test, alpha = 0.05. We compared our results with other published series studying resident and attending accuracy. RESULTS: A total of 141,381 cases were entered into the database during the review period. Of all examinations, 95.7% had zero variance, 3.3% minor variance, and 1.0% major variance. There was a slight, statistically significant increase in overall accuracy with increased resident year from 95.4% of examinations read by first-year residents (R1s) to 96.1% by fourth-year resident (R4s) (P < .0001). Overall percentages of exams with major discrepancies were 1.0% for R1s, 1.1% for second-year residents, 1.0% for third-year residents, and 0.98% for R4s. CONCLUSIONS: The majority of preliminary resident interpretations are highly accurate. The incidence of major discrepancies is extremely low and similar, even with R1s, to that of attending radiologists published in other studies. A slight, statistically significant decrease in the error rate is detectable as residents gain experience throughout the 4 years of residency.     

Preliminary interpretations of after-hours CT and sonography by radiology residents versus final interpretations by body imaging radiologists at a level 1 trauma center

OBJECTIVE: At many academic institutions, preliminary interpretations of CT scans and sonograms obtained after regular hours of operation are performed by radiology residents, with attending radiologists reviewing the interpretations the next morning. We sought to determine the rate of discrepancy between residents' interpretations of imaging studies and the final interpretations performed by an attending body imaging radiologist as well as any resulting clinical consequences stemming from the discrepancies. Therefore, we reviewed 928 CT and sonographic images that had been obtained after hours at a level 1 trauma center during a 6-month period. MATERIALS AND METHODS: Any discrepancies between the preliminary and final interpretations were judged as either major (i.e., necessitating an urgent change in treatment) or minor errors. We conducted patient follow-up via a retrospective review of the medical charts to determine whether any of the discrepancies led to additional imaging, an increase in patient morbidity, an extension of a hospital stay, or a change in treatment. RESULTS: The overall discrepancy rate in interpretations rendered by the residents and those performed by the attending radiologist was 3.8%, with most of these discrepancies (86%) judged to be minor. If we combined the data for body CT scans and sonograms, the rate of minor discrepancies was 3.2%, and the rate of major discrepancies was 0.5%. If we considered only body CT data in the evaluation, the overall discrepancy rate increased to 6.4%, with a 5.4% rate of minor discrepancies and a 1.0% rate of major discrepancies. CONCLUSION: Our evaluation of discrepancy rates was unusual in that we included interpretations of sonograms, on which residents and the attending radiologist had a higher rate of agreement (99.5%). Because of the high agreement in the interpretation of sonograms, the overall discrepancy rate was 3.8%. However, if only body CT scan interpretations were evaluated, our results were closer to the rates reported in previously published studies. Major discrepancies led to a change in patient treatment but did not lead to any increase in patient morbidity or to any quantifiable increase in the length of the hospital stay.     

Evaluation of suspected appendicitis in children and young adults: helical CT

PURPOSE: To evaluate the accuracy of helical computed tomography (CT) for the diagnosis of appendicitis in children and to assess the utility of CT in establishing alternative diagnoses. MATERIALS AND METHODS: The medical records of 154 children (median age, 12 years; age range, 1-20 years) who were suspected to have appendicitis and who underwent CT were reviewed. The gastrointestinal tract was opacified in 151 of 154 patients: Only orally administered contrast material was used in 126 patients; only rectally administered contrast material, in 21 patients; and both oral and rectal contrast material, in four patients. CT findings were correlated with surgical and histopathologic findings or with clinical follow-up findings. RESULTS: Sixty-four CT scans were interpreted as positive for appendicitis and included 58 true-positive and six false-positive scans. Ninety scans were interpreted as negative and included 87 true-negative and three false-negative scans. CT had a sensitivity of 95% and a specificity of 94% for the diagnosis of appendicitis. In addition, in 32 (34%) of 93 patients without appendicitis, an alternative diagnosis was established on the basis of CT findings. CONCLUSION: Helical CT is useful in a pediatric population to diagnose or exclude appendicitis and to establish an alternative diagnosis.     

Preliminary Reports in the Emergency Department: Is a Subspecialist Radiologist More Accurate Than a Radiology Resident?

RATIONALE AND OBJECTIVES: To determine whether emergency department (ED) preliminary reports rendered by subspecialist attending radiologists who are reading outside their field of expertise are more accurate than reports rendered by radiology residents, and to compare error rates between radiologists and nonradiologists in the ED setting. MATERIALS AND METHODS: The study was performed at a large academic medical center with a busy ED. An electronic preliminary report generator was used in the ED to capture preliminary interpretations rendered in a clinical setting by radiology residents, junior attendings (within 2 years of taking their oral boards), senior attendings, and ED clinicians between August 1999 and November 2004. Each preliminary report was later reviewed by a final interpreting radiologist, and the preliminary interpretation was adjudicated for the presence of substantial discordances, defined as a difference in interpretation that might immediately impact the care of the patient. Of the 612,890 preliminary reports in the database, 65,780 (11%) met inclusion criteria for this study. A log-linear analysis was used to assess the effects of modality and type of author on preliminary report error rates. RESULTS: ED clinicians had significantly higher error rates when compared with any type of radiologist, regardless of modality. Within the radiologists, residents and junior attendings had lower error rates than did senior attendings, but the differences were not statistically significant. CONCLUSION: Subspecialized attending radiologists who interpret ED examinations outside their area of expertise have error rates similar to those of radiology residents. Nonradiologists have significantly higher error rates than radiologists and radiology residents when interpreting examinations in the ED.     

Too Scared to Teach? The Unintended Impact of 360-Degree Feedback on Resident Education

Rationale and ObjectivesIn 2000, the Accreditation Council for Graduate Medical Education created a 360-degree feedback toolkit intended to provide residents with frequent feedback from both their peers and attending supervisors to address any deficiencies prior to graduation. At our institution, resident evaluations of faculty directly impact faculty pay and promotion. We aimed to evaluate attending physician's attitudes toward 360-degree feedback systems, specifically related to resident performance.Materials and MethodsAttending radiologists in a single-institution radiology residency program answered a 10-question survey regarding their views on 360-degree feedback systems. Fisher's exact tests were used to compare proportions.ResultsSeventeen of 24 (71%) attending physicians completed the survey. Of the respondents, 71% indicated that resident evaluations of attendings had an impact on job promotion and/or salaries; 65% indicated an impact on teaching quality; and 41% indicated an impact on their job security. All (100%) attendings indicated they felt comfortable giving positive written resident feedback, while 65% felt comfortable giving negative written feedback (P = 0.018). All (100%) attendings indicated they were comfortable giving positive verbal resident feedback, while 71% were comfortable giving negative verbal feedback (P = 0.044).ConclusionsAttendings were less comfortable giving negative written and verbal resident feedback than positive feedback. Most attendings believed that negative resident evaluations of attendings had an impact on their pay and promotion. Attendings may be more willing to provide honest feedback to residents in a 360-degree system that does not link resident evaluations to faculty pay and promotion.     

Clinical consequences of misinterpretations of neuroradiologic CT scans by on-call radiology residents

BACKGROUND AND PURPOSE: Studies have looked at the accuracy of radiologic interpretations by radiology residents as compared with staff radiologists with regard to emergency room plain films, emergency room body CT scans, and trauma head CT scans; however, to our knowledge, no study has evaluated on-call resident interpretations of all types of neuroradiologic CT scans. Both as a part of our departmental quality control program and to address concerns of clinical services about misinterpretation of neuroradiologic CT scans by on-call radiology residents, we evaluated the frequency of incorrect preliminary interpretations of neuroradiologic CT scans by on-call radiology residents and the effect of such misinterpretations on clinical management and patient outcome. METHODS: As determined by the staff neuroradiologist the next day, all potentially clinically significant changes to preliminary reports of emergency neuroradiologic CT scans rendered by on-call radiology residents were recorded over a 9-month period. A panel of neuroradiologists reviewed and graded all the changed cases by consensus. An emergency department staff physician reviewed medical records of all submitted cases to determine clinical consequences of the misinterpretations. RESULTS: Significant misinterpretations were made in 21 (0.9%) of 2388 cases during the study period. There was a significant change in patient management in 12 of the cases, with a potentially serious change in patient outcome in two cases (0.08%). CONCLUSION: On-call radiology residents have a low rate of significant misinterpretations of neuroradiologic CT scans, and the potential to affect patient outcome is rare.     

Overnight shift work: factors contributing to diagnostic discrepancies

The aims of the study are to identify factors contributing to preliminary interpretive discrepancies on overnight radiology resident shifts and apply this data in the context of known literature to draw parallels to attending overnight shift work schedules. Residents in one university-based training program provided preliminary interpretations of 18,488 overnight (11 pm–8 am) studies at a level 1 trauma center between July 1, 2013 and December 31, 2014. As part of their normal workflow and feedback, attendings scored the reports as major discrepancy, minor discrepancy, agree, and agree—good job. We retrospectively obtained the preliminary interpretation scores for each study. Total relative value units (RVUs) per shift were calculated as an indicator of overnight workload. The dataset was supplemented with information on trainee level, number of consecutive nights on night float, hour, modality, and per-shift RVU. The data were analyzed with proportional logistic regression and Fisher’s exact test. There were 233 major discrepancies (1.26 %). Trainee level (senior vs. junior residents; 1.08 vs. 1.38 %; p?<?0.05) and modality were significantly associated with performance. Increased workload affected more junior residents’ performance, with R3 residents performing significantly worse on busier nights. Hour of the night was not significantly associated with performance, but there was a trend toward best performance at 2 am, with subsequent decreased accuracy throughout the remaining shift hours. Improved performance occurred after the first six night float shifts, presumably as residents acclimated to a night schedule. As overnight shift work schedules increase in popularity for residents and attendings, focused attention to factors impacting interpretative accuracy is warranted.     

Imaging evaluation of suspected appendicitis in a pediatric population: effectiveness of sonography versus CT

OBJECTIVE. The purpose of this study was to compare the diagnostic accuracy of graded compression sonography with that of helical CT for the diagnosis of appendicitis in a pediatric and young adult population. SUBJECTS AND METHODS. Between June 1996 and April 1999, 386 pediatric and young adult patients with suspected appendicitis were examined using sonography, CT, or both: 233 underwent sonography only, 71 underwent CT only, and 82 underwent sonography and CT. All sonograms and CT scans were prospectively interpreted as showing positive or negative findings for appendicitis by one of six pediatric radiologists. CT and sonographic findings were correlated with surgical and histopathologic findings or findings at clinical follow-up. RESULTS. Helical CT had a significantly higher sensitivity (95% versus 78%, p = 0.009) and accuracy (94% versus 89%, p = 0.05) than graded compression sonography for the diagnosis of appendicitis in children, adolescents, and young adults. The specificity of both techniques was 93%. Twenty of 82 patients who underwent both sonography and CT had discordance between the findings of the two examinations. The CT results were correct in a significantly greater number of patients with discordant examinations (17/20 patients [85%]). CONCLUSION. Helical CT has a significantly higher sensitivity and accuracy than graded compression sonography for the diagnosis of appendicitis in a pediatric and young adult population, particularly in children more than 10 years old.     

Comparison of on-call radiology resident and faculty interpretation of 4- and 16-row multidetector CT pulmonary angiography with indirect CT venography

RATIONALE AND OBJECTIVES: On-call radiology residents frequently interpret computed tomography (CT) pulmonary angiography and CT venography studies outside of routine working hours. The purpose of this study was to compare resident and faculty interpretation concordance rates and to see if concordance rates differed depending on the number of CT detectors used. MATERIALS AND METHODS: The study population included 122 consecutive CT pulmonary angiography (CTPA) and CT venography (CTV) examinations performed on a four-row multidetector CT (MDCT) and 125 consecutive CTPA examinations performed using a 16-row MDCT scanner with CTV performed in 124 patients. Preliminary resident reports and final faculty reports were compared. Discrepant cases were independently reviewed by three cardiothoracic radiologists who were unaware of the initial interpretations. Interpretation concordance rates were calculated for both 4- and 16- row MDCT studies and compared using Fisher's exact test. RESULTS: Resident and faculty CTPA and CTV interpretations were concordant in 80% of the 4-row cases and 94% of the 16-row cases. When comparing resident interpretation to the final expert reference standard, the corrected resident error rate was 11% and 2% for 4-row CTPA and CTV, respectively and 4% and 2% for 16-row CTPA and CTV, respectively. Overall CTPA and CTV concordance was significantly lower for 4-row MDCT (80% versus 94%, P < .001 [two-sided] by Fisher's exact test). CONCLUSIONS: Radiology resident interpretation of CTPA and CTV studies demonstrates a high level of agreement with radiology faculty interpretation. Concordance rates are significantly higher for 16-row MDCT than 4-row MDCT which may be due to improved image quality.