Resident interpretation of emergency CT scans in the evaluation of acute appendicitis

Diagnostic Efficiency of Multidetector Computed Tomography in the Evaluation of Clinically Equivocal Cases of Acute Appendicitis with Surgical Correlation

Acute appendicitis is one of the most frequent causes of lower abdominal pain and requires immediate surgical intervention. The diagnosis often poses a lot of challenge even to experienced surgeon. Those patients with equivocal symptoms may require different imaging modalities like radiography, contrast examination and ultrasound with limited utility. Multidetector computed tomography (MDCT) used in suspected acute appendicitis has, however, resulted in improved diagnostic accuracy and also reduction of negative surgeries. Objective We intend to determine the diagnostic efficiency of MDCT in clinically equivocal cases of acute appendicitis correlating it with surgical/histopathological findings. Materials and methods A group of 116 patients was included in this study. Spiral MDCT was performed in all these cases after administration of oral and intravenous contrast. All these patients underwent surgery and the CT findings were correlated with histopathology. Out of these 116 patients, 60 patients were male and 56 female. The age range was from three to seventy years and mean age was 28+1 years. Results The results proved that MDCT had a sensitivity of 97.5%, specificity of 97.0%, and accuracy of 97.4% for the diagnosis of appendicitis with one false positive and two false negative cases. The study showed 100% accuracy in diagnosing acute appendicitis in children. In 33 patients, an alternate cause was identified with CT. The alternate diagnosis made on CT findings was consistent with the final diagnosis in 27 (81.8%) of 33 patients in whom there was no evidence of acute appendicitis. The clinical diagnosis disagreed with the CT diagnosis in six patients (18.18%). Conclusion Our study verifies that MDCT plays an important role in evaluation and consequent management of equivocal cases of acute appendicitis. MDCT is also able to diagnose appendicitis or detect alternative diagnosis in pediatric population.

The Accuracy of the Computed Tomography Diagnosis of Acute Appendicitis: Does the Experience of the Radiologist Matter?

Background and Aims:

To assess the accuracy of computed tomography in diagnosing acute appendicitis with a special reference to radiologist experience.

Material and Methods:

Data were collected prospectively in our randomized controlled trial comparing surgery and antibiotic treatment for uncomplicated acute appendicitis (APPAC trial, NCT01022567). We evaluated 1065 patients who underwent computed tomography for suspected appendicitis. The on-call radiologist preoperatively analyzed these computed tomography images. In this study, the radiologists were divided into experienced (consultants) and inexperienced (residents) ones, and the comparison of interpretations was made between these two radiologist groups.

Results:

Out of the 1065 patients, 714 had acute appendicitis and 351 had other or no diagnosis on computed tomography. There were 700 true-positive, 327 true-negative, 14 false-positive, and 24 false-negative cases. The sensitivity and the specificity of computed tomography were 96.7% (95% confidence interval, 95.1–97.8) and 95.9% (95% confidence interval, 93.2–97.5), respectively. The rate of false computed tomography diagnosis was 4.2% for experienced consultant radiologists and 2.2% for inexperienced resident radiologists (p = 0.071). Thus, the experience of the radiologist had no effect on the accuracy of computed tomography diagnosis.

Conclusion:

The accuracy of computed tomography in diagnosing acute appendicitis was high. The experience of the radiologist did not improve the diagnostic accuracy. The results emphasize the role of computed tomography as an accurate modality in daily routine diagnostics for acute appendicitis in all clinical emergency settings.

Variability in Observer Performance Between Faculty Members and Residents Using Breast Imaging Reporting and Data System (BI-RADS)-Ultrasound, Fifth Edition (2013)

Background

Ultrasonography (US) is a useful tool for breast imaging, yet is highly operator-dependent.

Objectives

We evaluated inter-observer variability and performance discrepancies between faculty members and radiology residents when describing breast lesions, by the fifth edition of breast imaging reporting and data system (BI-RADS)-US lexicon, and then attempted to identify whether inter-observer variability could be improved after one education session.

Patients and Methods

In total, 50 malignant lesions and 70 benign lesions were considered in our retrospective study. Two faculty members, two senior residents, and two junior residents separately assessed the US images. After the first assessment, the readers received one education session, and then reassessed the images in a random order. Inter-observer variability was measured using the kappa coefficient (κ). Performance discrepancy was evaluated by receiver operating characteristic (ROC) curves.

Results

For the faculty members, fair-to-good agreement was obtained in all descriptors and final assessment, while for residents, poor-to-moderate agreement was obtained. The areas under the ROC curves were 0.78 for the faculty members, 0.59 for the senior residents, and 0.52 for the junior residents, respectively. Diagnostic performance was significantly higher in the faculty members than the senior and junior residents (P = 0.0001 and < 0.0001, respectively). After one education session, the agreement in the final assessment was one level higher in the faculty members and senior residents, yet in the senior residents, the degree of agreement was still only fair. Moreover, in the junior residents, there was no improvement.

Conclusion

Investigative assessment of breast US by residents is inadvisable. We recommend continued professional resident training to improve the degree of agreement and performance.

CT in adults: systematic review and meta-analysis of interpretation discrepancy rates

PURPOSE

To use meta-analysis to determine the discrepancy rate when interpreting computed tomography (CT) studies performed in adult patients and to determine whether discrepancy rate differs on the basis of body region or level of radiologist training.

MATERIALS AND METHODS

MEDLINE and EMBASE were searched from 1946 to June 2012 by using the combination "radiology AND (error OR peer review)." Two reviewers independently selected studies that met the inclusion criteria and extracted study data. Total and major discrepancy rates were investigated with a random-effects meta-analysis, and subgroups were compared by using the χ(2) Q statistic. Subgroup analyses were performed on the basis of the level of training of the initial radiologist and the body system scanned.

RESULTS

Fifty-eight studies met the inclusion criteria (388 123 CT examinations). The pooled total discrepancy rate was 7.7% (95% confidence interval [CI]: 5.6%, 10.3%), and the major discrepancy rate was 2.4% (95% CI: 1.7%, 3.2%). The pooled major discrepancy rate was comparable for staff (2.9%; 95% CI: 1.2%, 6.7%) and residents (2.2%; 95% CI: 1.7%, 2.9%) (Q = 0.92, P = .633). The pooled major discrepancy rates for head CT (0.8%; 95% CI: 0.4%, 1.6%) and spine CT (0.7%; 95% CI: 0.2%, 2.7%) were lower than those for chest CT (2.8%; 95% CI: 1.5%, 5.4%) and abdominal CT (2.6%; 95% CI: 1.0%, 6.7%) (Q = 8.28, P = .041). Lack of blinding of the reference radiologist to the initial report was associated with a lower major discrepancy rate (2.0%; 95% CI: 1.4%, 2.7%; 43 studies) than when blinding was present (12.1%; 95% CI: 4.4%, 29.4%; five studies) (Q = 10.65, P = .001).

CONCLUSION

Potentially useful reference ranges were identified in the subgroup analyses on the basis of body region scanned at adult CT. However, considerable heterogeneity that is only partially explained by subgroup analysis signifies that further research is necessary--particularly regarding the question of blinding of the reference radiologist.

Handheld device review of abdominal CT for the evaluation of acute appendicitis

Advances in handheld computing now allow review of DICOM datasets from remote locations. As the diagnostic ability of this tool is unproven, we evaluated the ability to diagnose acute appendicitis on abdominal CT using a mobile DICOM viewer. This HIPAA compliant study was IRB-approved. Twenty-five abdominal CT studies from patients with RLQ pain were interpreted on a handheld device (iPhone) using a DICOM viewer (OsiriX mobile) by five radiologists. All patients had surgical confirmation of acute appendicitis or follow-up confirming no acute appendicitis. Studies were evaluated for the ability to find the appendix, maximum appendiceal diameter, presence of an appendicolith, periappendiceal stranding and fluid, abscess, and an assessment of the diagnosis of acute appendicitis. Results were compared to PACS workstation. Fifteen cases of acute appendicitis were correctly identified on 98% of interpretations, with no false-positives. Eight appendicoliths were correctly identified on 88% of interpretations. Three abscesses were correctly identified by all readers. Handheld device measurement of appendiceal diameter had a mean 8.6% larger than PACS measurements (p = 0.035). Evaluation for acute appendicitis on abdominal CT studies using a portable device DICOM viewer can be performed with good concordance to reads performed on PACS workstations.

A systematic review: the effect of clinical supervision on patient and residency education outcomes

PURPOSE

To summarize the literature regarding the effect of clinical supervision on patient and educational outcomes, especially in light of the recent (2010) Accreditation Council for Graduate Medical Education report that recommends augmented supervision to improve resident education and patient safety.

METHOD

The authors searched the English-language literature from 1966 to 2010 using electronic databases and a hand search. They included studies that described a controlled design, and they have relayed the effects of supervision on patient- and education-related outcomes. Two authors abstracted prescribed data from the reviewed studies. The authors rated the quality of each study using the Medical Education Research Study Quality Instrument.

RESULTS

Twenty-four articles across a variety of specialties (i.e., psychiatry, emergency medicine, surgery, anesthesia, and internal medicine) met inclusion criteria. Studies demonstrated that enhanced supervision in already-supervised activities resulted in improved patient- or education-related outcomes. Studies were limited by small sample sizes, nonrandomized designs, and a lack of objective measures of clinical supervision.

CONCLUSIONS

Enhanced clinical supervision of trainees has been associated with improved patient- and education-related outcomes in published studies. Future work should focus on developing validated measures of the effects of clinical supervision.

Computed tomographic scan diagnosis of appendicitis in children by pediatric and adult radiologists

OBJECTIVES

Computed tomographic (CT) scans are an accepted radiographic mode to the diagnosis of appendicitis. Radiologists play a critical role in its diagnostic accuracy. The purpose of this study was to determine whether there is a difference in the diagnostic accuracy between pediatric and general radiologists interpreting pediatric abdominal/pelvic CT scans for appendicitis.

METHODS

Computed tomographic scans of 10 patients (5 with appendicitis and 5 without appendicitis) were presented on a password-protected Web site. Radiologists rated the CT scans for the likelihood of appendicitis on a grading scale from 1 to 5.

RESULTS

This is a report of data from 6 pediatric radiologists and 13 general radiologists. For appendicitis cases, the pediatric radiologists gave a "positive" interpretation in 26 (87%) of the cases, whereas the general radiologists gave a "positive" interpretation in 57 (89%) of the cases. Of the true positives, pediatric radiologists rated 25 (96%) of 26 as a high likelihood of appendicitis with a score of 1, whereas general radiologists rated 44 (77%) of 57 as high likelihood. In cases without appendicitis, the pediatric radiologists had a true negative interpretation rate of 83%, and the general radiologists had a true negative interpretation rate of 73%. Of the true negatives, pediatric radiologists rated 22 (88%) of 25 with a rating of 4, being "no appendicitis," whereas the general radiologists rated 39 (85%) of 46 with a rating of 4.

CONCLUSIONS

There is a similar accuracy rate in the interpretation of CT scans positive for appendicitis between general and pediatric radiologists, but pediatric radiologists were more definitive.

Out of hours multidetector computed tomography pulmonary angiography: are specialist resident reports reliable?

RATIONALE AND OBJECTIVES

The purposes of this study were to assess the accuracy of trainee radiologists' reports for computed tomographic pulmonary angiographic (CTPA) imaging and to determine agreement or discrepancy with final verified consultant reports.

MATERIALS AND METHODS

A total of 100 consecutive out-of-hours CTPA examinations were prospectively analyzed. Fifty-one male and 49 female subjects were included in the study. The mean age of patients scanned was 63.7 years (range, 17-98 years).

RESULTS

Eighteen of the 100 subjects (18%) had findings positive for pulmonary embolism. The interobserver agreement for pulmonary embolism between on-call radiology residents and consultant radiologists was almost perfect (κ = 0.932; 95% confidence interval, 0.84-1.0; P < .0001). There was one false-negative CTPA report. Eighty-two CTPA scans (82%) were reported as negative for pulmonary embolism by consultant radiologists. In this group, there was a single false-positive interpretation by the on-call specialist resident. The interobserver agreement for all findings between resident and consultant reports was almost perfect (weighted κ = 0.87; 95% confidence interval, 0.79-0.96; P < .0001). The overall discrepancy rate, including both false-positive and false-negative findings, between the on-call radiology resident and consultant radiologist was 8% (eight of 100).

CONCLUSIONS

CTPA reports by radiology residents can be relied and acted upon without any major discrepancies. There is a relatively much higher proportion of patients with alternative diagnoses, mainly infective consolidation and heart failure presenting with similar symptoms and signs as pulmonary emboli. It is imperative for trainees to be systematic and review all images if observational omissions are to be reduced.

Discordance rates between preliminary and final radiology reports on cross-sectional imaging studies at a level 1 trauma center

RATIONALE AND OBJECTIVES

The goal was to determine discordance rates between preliminary radiology reports provided by on-call radiology house staff and final reports from attending radiologists on cross-sectional imaging studies requested by emergency department staff after hours.

MATERIALS AND METHODS

A triplicate carbon copy reporting form was developed to provide permanent records of preliminary radiology reports and to facilitate communication of discrepant results to the emergency department. Data were collected over 21 weeks to determine the number of discordant readings. Patients' medical records were reviewed to show whether discrepancies were significant or insignificant and to assess their impact on subsequent management and patient outcome.

RESULTS

The emergency department requested 2830 cross-sectional imaging studies after hours and 2311 (82%) had a copy of the triplicate form stored in radiology archives. Discrepancies between the preliminary and final report were recorded in 47 (2.0%), with 37 (1.6%) considered significant: 14 patients needed no change, 13 needed a minor change, and 10 needed a major change in subsequent management. Ten (0.43%) of the discordant scans were considered insignificant. A random sample of 104 (20%) of the 519 scans without a paper triplicate form was examined. Seventy-one (68%) did have a scanned copy of the triplicate form in the electronic record, with a discrepancy recorded in 3 (4.2%), which was not statistically different from the main cohort (P = .18).

CONCLUSION

Our study suggests a high level of concordance between preliminary reports from on-call radiology house staff and final reports by attending subspecialty radiologists on cross-sectional imaging studies requested by the emergency department.

Radiology resident interpretation of on-call CT pulmonary angiograms

RATIONALE AND OBJECTIVES

To evaluate the interpretation of computed tomographic pulmonary angiograms performed outside of regular reporting hours, comparing the initial interpretation by the radiology resident to the attending radiologist.

MATERIALS AND METHODS

Records for 840 consecutive computed tomographic pulmonary angiograms (CTPA) performed outside of regular reporting hours at two tertiary referral centers from January 1, 2004-December 31, 2005 were reviewed. The preliminary interpretation by the on-call radiology resident was compared to the subsequent final report issued by a subspecialty trained chest radiologist. Studies were stratified as positive, negative, or equivocal for pulmonary embolus. Cases with discordant interpretations or negative CTPA were reviewed to determine impact on clinical outcome. Patients were followed up to 12 months after CTPA to document any subsequent thromboembolic event.

RESULTS

Sixteen percent (131/840) of CTPAs were reported positive by the staff radiologist. There was agreement in 90% (752/840) of studies (P = .76, 95% confidence interval, 0.71-0.81) with 86% (114/133) agreement for studies interpreted as positive by residents, 95% (582/612) for studies interpreted as negative by residents, and 63% (60/95) for studies interpreted as equivocal by residents. Studies of optimal quality had higher interobserver agreement than studies of suboptimal quality (P < .0001). In-patient studies were more likely to be positive than emergency room patients (20% vs. 13%) (P = .004). No adverse clinical outcomes were attributed to discordant interpretations.

CONCLUSIONS

Radiology residents provide a high level interpretation of on-call CTPA studies, achieving good concordance with the attending radiologists' assessment.

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.

Academic Radiologists’ On-Call and Late-Evening Duties

On-call and late-evening duties have increased dramatically for radiologists, be they in private practice, at academic medical centers, or at state or federal government health care facilities. Most busy medical centers in North America require around-the-clock radiology interpretations for emergent or urgent patients, particularly if they are level 1 trauma centers. Coverage by attending radiologists around the clock is expensive and difficult to implement. In this study, an e-mail questionnaire was sent to 83 members of the Society of Chairmen of Academic Radiology Departments concerning general radiologists' on-call and after-hours duties. Detailed replies were received from 29 academic medical centers, all of which were university owned or affiliated. There was complex variation on how academic radiology departments approached their after-hours commitments, but only 10% of academic institutions (3 of 29) answering the survey had 24-hour in-house coverage by general radiologists. Coverage by attending radiologists around the clock at academic medical centers is not the current standard of practice at most academic medical centers.

Preliminary Radiology Resident Interpretations Versus Final Attending Radiologist Interpretations and the Impact on Patient Care in a Community Hospital

OBJECTIVE

At academic institutions, overnight emergency radiology examinations are interpreted by the on-call radiology resident and are reviewed by an attending radiologist in the morning. The objective of our study was to determine the rate of discrepancies between the two interpretations and the possible effect, if any, on patient care.

MATERIALS AND METHODS

The preliminary reports for 11,908 emergency diagnostic imaging examinations interpreted after hours by residents over a 3-year period (January 2002-January 2005) were reviewed retrospectively for any discrepancy with the attending radiologist's final interpretation. A discrepancy was noted if verbal notification of the ordering physician was required. The medical charts of the cases for which there was a major discrepancy between the two interpretations were reviewed. The discrepancies were categorized as to the effect on patient morbidity. The resident discrepancy rates were also compared with RADPEER data from our institution.

RESULTS

The overall major discrepancy rate was 2.6%. This rate is comparable to RADPEER data, which found a misinterpretation rate of 2.1%. The technique most commonly involved in cases with discrepant interpretations was contrast-enhanced CT of the abdomen and pelvis, with the most common diagnosis related to acute appendicitis (total of 21 cases). The rate of discrepancy was highest for residents who were in their third year of training. The indications for these examinations varied; however, the effect on patient management was no significant effect in 92.8%, some negative effect in 6.9%, and significant negative effect in 0.3%.

CONCLUSION

The results of this investigation highlight the minimal discrepancy rate that occurs with overnight resident coverage. Thus, there is no detrimental effect on the quality of patient care from relying on preliminary interpretations made by radiology residents.

Discrepancies in interpretation of ED body computed tomographic scans by radiology residents

OBJECTIVE

In academic institutions, radiology residents are often relied on for providing preliminary reports of imaging studies done in the ED. We examined the prevalence of discrepant interpretations of body computed tomographic (CT) scans in our institution.

METHODS

We conducted a retrospective study on a consecutive series of body CT scans at an urban ED. We compared the preliminary interpretation by radiology residents with the final interpretation by radiology attending physicians. An interpretation was characterized as having no discrepancy, minor discrepancy, or major discrepancy. A major discrepancy was defined as a discrepancy that resulted in a change in diagnosis, treatment, or disposition.

RESULTS

Two hundred three body CT scans were identified during the study period. Of these CT scans, 20 had major discrepancies (10%), 40 had minor discrepancies (20%), and 143 had no discrepancy (70%). Major discrepancies included missed appendicitis, normal appendix, missed bowel obstruction, and missed colon cancer. Computed tomographic scans with abnormal findings were more likely to contain major discrepancies (relative risk = 6.0; 95% confidence interval = 1.8-2.0).

CONCLUSION

Discrepancies between radiology residents and radiology attending physicians were common at our institution. Emergency department physicians should exercise caution when relying on residents' interpretation of body CT scans.

Added value of coronal reformations for duty radiologists and for referring physicians or surgeons in the CT diagnosis of acute appendicitis

Objective

To assess the added value of coronal reformation for radiologists and for referring physicians or surgeons in the CT diagnosis of acute appendicitis.

Materials and Methods

Contrast-enhanced CT was performed using 16-detector-row scanners in 110 patients, 46 of whom had appendicitis. Transverse (5-mm thickness, 4-mm increment), coronal (5-mm thickness, 4-mm increment), and combined transverse and coronal sections were interpreted by four radiologists, two surgeons and two emergency physicians. The area under the receiver operating characteristic curve (Az value), sensitivity, specificity (McNemar test), diagnostic confidence and appendiceal visualization (Wilcoxon signed rank test) were compared.

Results

For radiologists, the additional coronal sections tended to increase the Az value (0.972 vs. 0.986, p = 0.076) and pooled sensitivity (92% [95% CI: 88, 96] vs. 96% [93, 99]), and enhanced appendiceal visualization in true-positive cases (p = 0.031). For non-radiologists, no such enhancement was observed, and the confidence for excluding acute appendicitis declined (p = 0.013). Coronal sections alone were inferior to transverse sections for diagnostic confidence as well as appendiceal visualization for each reader group studied (p < 0.05).

Conclusion

The added value of coronal reformation is more apparent for radiologists compared to referring physicians or surgeons in the CT diagnosis of acute appendicitis.

Reader error during CT colonography: causes and implications for training

This study investigated the variability in baseline computed tomography colonography (CTC) performance using untrained readers by documenting sources of error to guide future training requirements. Twenty CTC endoscopically validated data sets containing 32 polyps were consensus read by three unblinded radiologists experienced in CTC, creating a reference standard. Six readers without prior CTC training [four residents and two board-certified subspecialty gastrointestinal (GI) radiologists] read the 20 cases. Readers drew a region of interest (ROI) around every area they considered a potential colonic lesion, even if subsequently dismissed, before creating a final report. Using this final report, reader ROIs were classified as true positive detections, true negatives correctly dismissed, true detections incorrectly dismissed (i.e., classification error), or perceptual errors. Detection of polyps 1-5 mm, 6-9 mm, and > or =10 mm ranged from 7.1% to 28.6%, 16.7% to 41.7%, and 16.7% to 83.3%, respectively. There was no significant difference between polyp detection or false positives for the GI radiologists compared with residents (p=0.67, p=0.4 respectively). Most missed polyps were due to failure of detection rather than characterization (range 82-95%). Untrained reader performance is variable but generally poor. Most missed polyps are due perceptual error rather than characterization, suggesting basic training should focus heavily on lesion detection.

Incidence of acute appendicitis in patients with equivocal CT findings

OBJECTIVE

The purpose of our study was to determine the incidence of acute appendicitis in patients for whom the CT interpretation is deemed equivocal.

MATERIALS AND METHODS

Of 1,344 patients referred for CT with suspected appendicitis between January 1998 and December 2002, 172 patients were identified in whom the radiographic findings were equivocal. Two radiologists reviewed the equivocal CT cases, reassessing appendiceal size and the presence of right lower quadrant stranding, fluid, or an appendicolith. The reviewers' findings were correlated with surgical pathology reports and clinical follow-up.

RESULTS

Fifty-three (31%) of 172 patients with indeterminate findings on CT scans were subsequently diagnosed with appendicitis. For reviewers 1 and 2, respectively, appendicitis was present in five (14%) of 36 and six (13%) of 47 patients who had isolated appendiceal diameter less than 9 mm, and in 11 (52%) of 21 and in 10 (50%) of 20 patients who had isolated appendiceal dilatation equal to or greater than 9 mm. If a normal diameter appendix (< 6 mm) was visualized in a patient who had right lower quadrant stranding or fluid, appendicitis was present in only one (17%) of six and in four (27%) of 15 patients for reviewers 1 and 2, respectively. If the appendix could not be identified but there was right lower quadrant stranding or fluid, appendicitis was present in seven (37%) of 19 and in eight (53%) of 15 patients.

CONCLUSION

Appendicitis is encountered in about 30% of patients with equivocal findings on CT, and the diagnosis should be considered in most of these patients if they are appropriately symptomatic. However, when the appendix measures less than 9 mm alone, the likelihood of appendicitis is much smaller.

Current surgical opinion of computed tomography for acute appendicitis

BACKGROUND

Appendiceal computed tomography (CTA) for the diagnosis of acute appendicitis (AA) has become popular, with a growing body of literature reporting excellent rates of sensitivity, specificity, and accuracy (S/S/A). However, several studies indicate that the true S/S/A of CTA is lower than the best results reported, especially if the white blood count is normal, the reader is inexperienced, or the study is obtained in the absence of surgical consultation. Thus, it is possible that skepticism of the value of CTA to diagnose AA may exist. Our objective was to determine the current knowledge of and attitudes regarding CTA among practicing surgeons.

METHODS

Two thousand questionnaires were sent randomly to general surgeon Fellows of the American College of Surgeons. Questions detailed the surgeon's practice, experience, hospital characteristics, and opinion regarding the utility and use of CTA. The existence of a formal CTA protocol, its characteristics, and radiologist availability for CT interpretation were determined. Data were analyzed by x(2) with Fisher exact test, multiple-group x(2), and univariate ANOVA as appropriate. Results are reported as mean +/- SEM with significance accepted at p < 0.05.

RESULTS

The response rate was 27%. Mean age was 51 +/- 1 years, 60% of respondents were general surgeons, and 9% were laparoscopic surgeons. Seventy-four percent of respondents believe the accuracy rate of CTA is less than the originally reported 98%; those who disbelieve are less likely to utilize CTA (p < 0.0001). Sixty-two percent of respondents believe CTA is over-utilized; 43% obtain CTA in </=25% of patients, and 62% obtain CTA in fewer than 50% of patients. Only 36% of respondents had access to CTA by protocol; those surgeons were more likely to know protocol details (p < 0.0001). Emergency medicine physicians order CTA most often (63%), and studies are most often interpreted by an attending radiologist (69%).

CONCLUSIONS

Practicing surgeons are skeptical of the role of CTA for diagnosis of AA. Incorporation of CTA into practice is not widespread, perhaps because CTA by protocol is unavailable to most surgeons and because it is often obtained in the absence of surgical consultation.

Comparison of Interpretations of CT Angiograms in the Evaluation of Suspected Pulmonary Embolism by On-Call Radiology Fellows and Subsequently by Radiology Faculty

OBJECTIVE

Our objective was to evaluate interobserver variability in interpretations performed by on-call radiology fellows and subsequently by attending radiologists of CT angiograms obtained for clinically suspected pulmonary embolism and to evaluate factors contributing to discrepancies.

MATERIALS AND METHODS

Written interpretations made by on-call fellows were compared with reports approved by attending radiologists for all CT angiograms obtained for suspected pulmonary embolism after work hours and on weekends in a recent 19-month period. Interpretations were stratified as positive, negative, or equivocal for pulmonary embolism. In cases of discordant interpretations, those CT angiograms were rereviewed by two thoracic radiologists; then patient medical records were reviewed for evidence of clinical effect. Technical and patient-related reasons for discordant interpretations of CT angiograms were recorded.

RESULTS

Six hundred fifty-eight oncology patients were examined on CT angiography; five were examined twice. The fellows reported 137 CT angiograms (21%) as positive, 498 (75%) as negative, and 28 (4%) as equivocal for pulmonary embolism. Interpretations of the fellows and attending radiologists agreed in 93% (615/663) of CT angiograms (kappa = 0.80). The concordance rates for CT angiograms interpreted by fellows as positive (89%, 122/137), negative (96%, 479/498), and equivocal (50%, 14/28) were significantly different from each other (p < 0.001 for each). A significantly greater proportion of CT angiograms with discordant interpretations was reported to be technically limited (p < 0.01). No clear adverse clinical events were attributed to discordant interpretations of CT angiograms, although the death of one patient in that subgroup was of indeterminate cause.

CONCLUSION

In the evaluation of CT angiograms obtained for suspected pulmonary embolism, on-call fellows showed good agreement with attending radiologists. CT angiograms with discordant interpretations often were limited by technical or patient-related factors.

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.

Acute appendicitis: effect of increased use of CT on selecting patients earlier

PURPOSE

To explore the possibility of a relationship between increased use of computed tomography (CT) for diagnosis of appendicitis and increased occurrence of minimal or subtle CT and surgical findings.

MATERIALS AND METHODS

Two groups, each with 50 consecutive patients who underwent CT before appendectomy in 1997 and 2000, were compared. CT scans and surgery-pathology reports were evaluated on a six-grade scale from normal to abscess or inflammatory mass. The demographics, surgical techniques, hospital stay, and grade distribution for the two groups were compared, and the CT results were correlated with surgical findings.

RESULTS

In 1997, CT was performed in 33% (50 of 152) of patients undergoing appendectomy, as compared with 59% (50 of 85) 3 years later (P <.001). There was excellent correlation between surgical-pathologic and CT grades (weighted kappa, 0.75; P <.001; Spearman rank correlation, 0.83). There was no significant difference in demographics, rate of surgery, or surgical techniques used, but there was a significant decrease in the median surgical-pathologic grades, from 3.0 to 2.5 (P =.05) for all patients and from 3.5 to 2.6 (P =.003) for patients who underwent CT. Similarly, the median CT grade decreased from 4 to 3 (P <.001). Seven patients had subtle CT findings in 1997 compared with 16 in 2000 (P =.004), and there was a significant decrease in mean hospital stay, from 2.8 days +/- 4 (SD) to 1.5 days +/- 2 (P =.008).

CONCLUSION

With increased CT use, there were less severe imaging findings, including absence of periappendiceal stranding, and a significant decrease in surgical-pathologic severity of appendiceal disease and hospital stay.