Nonenhanced limited CT in children suspected of having appendicitis: prospective comparison of attending and resident interpretations

Value of Clinical Information on Radiology Reports in Oncological Imaging

Radiological reporting errors have a direct negative impact on patient treatment. The purpose of this study was to investigate the contribution of clinical information (CI) in radiological reporting of oncological imaging and the dependence on the radiologists’ experience level (EL). Sixty-four patients with several types of carcinomas and twenty patients without tumors were enrolled. Computed tomography datasets acquired in primary or follow-up staging were independently analyzed by three radiologists (R) with different EL (R1: 15 years; R2: 10 years, R3: 1 year). Reading was initially performed without and 3 months later with CI. Overall, diagnostic accuracy and sensitivity for primary tumor detection increased significantly when receiving CI from 77% to 87%; p = 0.01 and 73% to 83%; p = 0.01, respectively. All radiologists benefitted from CI; R1: 85% vs. 92%, p = 0.15; R2: 77% vs. 83%, p = 0.33; R3: 70% vs. 86%, p = 0.02. Overall, diagnostic accuracy and sensitivity for detecting lymphogenous metastases increased from 80% to 85% (p = 0.13) and 42% to 56% (p = 0.13), for detection of hematogenous metastases from 85% to 86% (p = 0.61) and 46% to 60% (p = 0.15). Specificity remained stable (>90%). Thus, CI in oncological imaging seems to be essential for correct radiological reporting, especially for residents, and should be available for the radiologist whenever possible.

Diagnostic Performance of a Staged Pathway for Imaging Acute Appendicitis in Children

INTRODUCTION

The objective of this work is to assess the performance of our staged diagnostic pathway in the evaluation of suspected appendicitis cases in children. The pathway consisted of clinical assessment by the emergency physician, performing initial ultrasound (US), consultation, and clinical reevaluation by the surgery team followed by a repeat focused US scan in inconclusive cases. Computed tomography (CT) was limited to cases where the repeat US remained inconclusive and the clinical reassessment indicated persistent concerns for appendicitis.

METHOD

Retrospective review of the electronic medical records of 206 consecutive children who presented to our emergency department with acute abdominal pain and underwent US examination for suspected appendicitis. The imaging findings, management plan, and surgical outcome (in those who underwent surgery) were reviewed. The diagnostic performance of the initial US, repeat US, and the full imaging protocol were evaluated including the negative appendectomy rate (NAR) and the number of CT scans performed.

RESULTS

Of the 206 cases, 73 (35.4%) had appendicitis. Computed tomography was performed in 9 (4.3%) of 206 cases. The US/CT ratio was 23:1. Our approach showed a diagnostic accuracy of 95.6% (197/206), sensitivity of 97.3% (73/75), specificity of 93.7% (124/133), positive predictive value of 89.0% (73/82), and negative predictive value of 98.7% (82/95). The NAR was 2.7% (2/72). The accuracy of the protocol is higher than that of the initial US alone (61.2%; 126/206) and that of the repeat US (84.2%; 16/19).

CONCLUSION

The strategy of repeating limited focused US followed by CT scan in cases that remain inconclusive has good diagnostic accuracy and reasonable NAR and decreases the number of CT scans.

Computed tomography for diagnosis of acute appendicitis in adults

BACKGROUND

Diagnosing acute appendicitis (appendicitis) based on clinical evaluation, blood testing, and urinalysis can be difficult. Therefore, in persons with suspected appendicitis, abdominopelvic computed tomography (CT) is often used as an add-on test following the initial evaluation to reduce remaining diagnostic uncertainty. The aim of using CT is to assist the clinician in discriminating between persons who need surgery with appendicectomy and persons who do not.

OBJECTIVES

Primary objective Our primary objective was to evaluate the accuracy of CT for diagnosing appendicitis in adults with suspected appendicitis. Secondary objectives Our secondary objectives were to compare the accuracy of contrast-enhanced versus non-contrast-enhanced CT, to compare the accuracy of low-dose versus standard-dose CT, and to explore the influence of CT-scanner generation, radiologist experience, degree of clinical suspicion of appendicitis, and aspects of methodological quality on diagnostic accuracy.

SEARCH METHODS

We searched MEDLINE, Embase, and Science Citation Index until 16 June 2017. We also searched references lists. We did not exclude studies on the basis of language or publication status.

SELECTION CRITERIA

We included prospective studies that compared results of CT versus outcomes of a reference standard in adults (> 14 years of age) with suspected appendicitis. We excluded studies recruiting only pregnant women; studies in persons with abdominal pain at any location and with no particular suspicion of appendicitis; studies in which all participants had undergone ultrasonography (US) before CT and the decision to perform CT depended on the US outcome; studies using a case-control design; studies with fewer than 10 participants; and studies that did not report the numbers of true-positives, false-positives, false-negatives, and true-negatives. Two review authors independently screened and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected the data from each study and evaluated methodological quality according to the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate random-effects model to obtain summary estimates of sensitivity and specificity.

MAIN RESULTS

We identified 64 studies including 71 separate study populations with a total of 10,280 participants (4583 with and 5697 without acute appendicitis). Estimates of sensitivity ranged from 0.72 to 1.0 and estimates of specificity ranged from 0.5 to 1.0 across the 71 study populations. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.93 to 0.96), and summary specificity was 0.94 (95% CI 0.92 to 0.95). At the median prevalence of appendicitis (0.43), the probability of having appendicitis following a positive CT result was 0.92 (95% CI 0.90 to 0.94), and the probability of having appendicitis following a negative CT result was 0.04 (95% CI 0.03 to 0.05). In subgroup analyses according to contrast enhancement, summary sensitivity was higher for CT with intravenous contrast (0.96, 95% CI 0.92 to 0.98), CT with rectal contrast (0.97, 95% CI 0.93 to 0.99), and CT with intravenous and oral contrast enhancement (0.96, 95% CI 0.93 to 0.98) than for unenhanced CT (0.91, 95% CI 0.87 to 0.93). Summary sensitivity of CT with oral contrast enhancement (0.89, 95% CI 0.81 to 0.94) and unenhanced CT was similar. Results show practically no differences in summary specificity, which varied from 0.93 (95% CI 0.90 to 0.95) to 0.95 (95% CI 0.90 to 0.98) between subgroups. Summary sensitivity for low-dose CT (0.94, 95% 0.90 to 0.97) was similar to summary sensitivity for standard-dose or unspecified-dose CT (0.95, 95% 0.93 to 0.96); summary specificity did not differ between low-dose and standard-dose or unspecified-dose CT. No studies had high methodological quality as evaluated by the QUADAS-2 tool. Major methodological problems were poor reference standards and partial verification primarily due to inadequate and incomplete follow-up in persons who did not have surgery.

AUTHORS' CONCLUSIONS

The sensitivity and specificity of CT for diagnosing appendicitis in adults are high. Unenhanced standard-dose CT appears to have lower sensitivity than standard-dose CT with intravenous, rectal, or oral and intravenous contrast enhancement. Use of different types of contrast enhancement or no enhancement does not appear to affect specificity. Differences in sensitivity and specificity between low-dose and standard-dose CT appear to be negligible. The results of this review should be interpreted with caution for two reasons. First, these results are based on studies of low methodological quality. Second, the comparisons between types of contrast enhancement and radiation dose may be unreliable because they are based on indirect comparisons that may be confounded by other factors.

Diagnostic performance of CT for pediatric patients with suspected appendicitis in various clinical settings: a systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic performance of CT for pediatric patients with suspected appendicitis in various clinical settings and the proportion of acute appendicitis on final diagnosis among equivocal CT findings.

METHODS

MEDLINE and EMBASE databases were searched until October 21, 2017, for studies investigating diagnostic performance of CT for acute appendicitis in pediatric patients confirmed by histopathologic findings and/or clinical follow-up. Pooled estimates of sensitivity and specificity were calculated using a hierarchical logistic regression modeling. The proportion of true appendicitis among patients with inconclusive CT results was obtained using fixed and random effects meta-analyses.

RESULTS

Twenty-two articles with 3396 patients were included. The pooled sensitivity and specificity were 95% (95% CI, 93-97%) and 94% (95% CI, 90-96%), respectively, and the area under the hierarchical summary receiver operating characteristic (HSROC) curve was 0.98 (95% CI, 0.96-0.99). Subgroup analyses revealed a comparable diagnostic performance in the low-dose CT group (sensitivity, 97%; specificity, 96%) and the unenhanced group (sensitivity, 95%; specificity, 95%). Other subgroups (publication year, study design, enrolled population, true appendicitis proportion, CT channel number, and slice thickness) also showed good diagnostic performance. Six studies reporting the true appendicitis proportion among patients with equivocal CT findings had pooled proportion of 17% (95% CI, 9-29%).

CONCLUSIONS

CT showed good performance for suspected appendicitis in pediatric patients under various clinical settings, including in cases with dose reduction or absence of IV contrast. The prevalence of true appendicitis among patients with equivocal appendicitis results on CTs was not low; therefore, clinical attention should not be disregarded in this population.

The accuracy of interpretation of emergency abdominal CT in adult patients who present with non-traumatic abdominal pain: results of a UK national audit

AIM

To evaluate major/minor discrepancy rates for provisional (initial) and addendum (supplementary senior review) emergency computed tomography (CT) reports in patients presenting with non-traumatic abdominal pain.

MATERIALS AND METHODS

Ethical approval for this type of study is not required in the UK. All radiology departments with an approved lead for audit registered with the Royal College of Radiologists were invited to participate in this retrospective audit. The first 50 consecutive patients (25 surgical, 25 non-surgical) who underwent emergency abdominal CT for non-traumatic abdominal pain in 2013 were included. Statistical analyses were performed to identify organisational and report/patient-related variables that might be associated with major discrepancy.

RESULTS

One hundred and nine (58%) of 188 departments supplied data to the study with a total of 4,931 patients (2,568 surgical, 2,363 non-surgical). The audit standard for provisional report major discrepancy was achieved for registrars (target <10%, achieved 4.6%), for on-site consultants (target <5%, achieved 3.1%) and consultant addendum (target <5%, achieved 2.9%). Off-site reporters failed to meet the standard target (<5%, achieved 8.7% overall and 12.7% in surgical patients). The standard for patients coming to harm was not met in the surgical group (target <1%, achieved 1.5%) and was narrowly missed overall (target <1%, achieved 1%).

CONCLUSION

This study should be used to provide impetus to improve aspects of out-of-hours CT reporting. Clear benefits of CT interpretation/review by on-site and more senior (consultant) radiologists have been demonstrated.

ACR Appropriateness Criteria® Right Lower Quadrant Pain--Suspected Appendicitis

The most common cause of acute right lower quadrant (RLQ) pain requiring surgery is acute appendicitis (AA). This narrative's focus is on imaging procedures in the diagnosis of AA, with consideration of other diseases causing RLQ pain. In general, Computed Tomography (CT) is the most accurate imaging study for evaluating suspected AA and alternative etiologies of RLQ pain. Data favor intravenous contrast use for CT, but the need for enteric contrast when intravenous contrast is used is not strongly favored. Radiation exposure concerns from CT have led to increased investigation in minimizing CT radiation dose while maintaining diagnostic accuracy and in using algorithms with ultrasound as a first imaging examination followed by CT in inconclusive cases. In children, ultrasound is the preferred initial examination, as it is nearly as accurate as CT for the diagnosis of AA in this population and without ionizing radiation exposure. In pregnant women, ultrasound is preferred initially with MRI as a second imaging examination in inconclusive cases, which is the majority.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Acute Appendicitis: Use of Clinical and CT Findings for Modeling Hospital Resource Utilization

OBJECTIVE

The purpose of this study was to retrospectively investigate associations between baseline CT findings in suspected acute appendicitis and subsequent hospital resource utilization.

MATERIALS AND METHODS

One hundred thirty-eight patients (76 male and 62 female patients; mean [± SD] age, 40 ± 21 years) who were admitted for suspected acute appendicitis and underwent baseline CT were included. A single radiologist reviewed CT examinations for appendiceal-related findings. Linear and logistic regressions were performed to identify independent predictors of payer and hospital resource utilization. Combined performance of identified independent factors for predicting outcomes was determined.

RESULTS

Greater age, lower Charlson comorbidity index (CCI), lesser appendiceal wall thickness, absence of loculated fluid collection, and absence of periappendiceal fluid were significant independent predictors of inpatient surgery (joint sensitivity, 92.7%; specificity, 65.8%). Smaller appendiceal diameter, absence of periappendiceal fluid, and laparoscopic surgery were significant independent predictors of same-day discharge (joint sensitivity, 79.1%; specificity, 64.2%). Greater CCI, greater wall thickness, and presence of periappendiceal fluid were significant independent predictors of repeat abdominopelvic CT (joint sensitivity, 82.5%; specificity, 68.1%). Presence of an appendicolith was the only significant predictor of repeat emergency department visit within 30 days (sensitivity, 61.2%; specificity, 68.8%) and the only significant predictor of repeat inpatient admission within 30 days (sensitivity, 63.6%; specificity, 68.5%). Greater appendiceal diameter and presence of free air were significant predictors of inpatient costs, and predicted costs were as follows: $8047 + ($745 × appendiceal diameter) if free air was absent; and $-39,261 + ($4426 × appendiceal diameter) if free air was present. However, costs were poorly predicted when greater than $45,000. Sex, WBC count, and payer category were not independent predictors, relative to CT findings, of any outcome.

CONCLUSION

Admission CT findings serve as independent predictors of hospital resource utilization in suspected acute appendicitis.

ACR Appropriateness Criteria® right lower quadrant pain--suspected appendicitis

The diagnostic imaging of patients presenting with right lower quadrant pain and suspected appendicitis may be organized according to age and gender and to the presence or absence of "classic" signs and symptoms of acute appendicitis. Among adult patients presenting with clinical signs of acute appendicitis, the sensitivity and specificity of CT are greater than those of ultrasound, with improved performance when CT is performed with intravenous contrast. The use of rectal contrast has been associated with decreased time in the emergency department. Computed tomography has also been shown to reduce cost and negative appendectomy rates. Both CT and ultrasound are also effective in the identification of causes of right lower quadrant pain unrelated to appendicitis. Among pediatric patients, the sensitivity and specificity of graded-compression ultrasound can approach those of CT, without the use of ionizing radiation. Performing MRI after inconclusive ultrasound in pregnant patients has been associated with sensitivity and specificity of 80% to 86% and 97% to 99%, respectively. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

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.

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.

Radiology residents' on-call interpretation of chest radiographs for congestive heart failure

RATIONALE AND OBJECTIVES

This study was designed to evaluate the performance of radiology residents in interpreting emergency department (ED) chest radiographs for congestive heart failure and to characterize the factors associated with a subsequent amended interpretation by an attending radiologist.

MATERIALS AND METHODS

We retrospectively reviewed all amended reports for ED chest radiographs between January 2004 and July 2005 and identified those with discrepant interpretations regarding the diagnosis of congestive heart failure. A total of 1.9% (476 of 24,600) of chest radiographs were amended over the study period. Forty-eight patients (75% female, mean age 66 years) whose chest radiograph was amended for the diagnosis of congestive heart failure and were available for review formed the study population. A control group of 35 patients (69% female, mean age 67 years) were individually matched to a convenience subset of patients by age, gender, clinical indication, and radiographic projection. Chest radiographs were in the anteroposterior projection in 62% (30 of 48) of study patients and 60% (21 of 35) of controls. A blinded expert panel of three board-certified cardiothoracic radiologists jointly reviewed each chest radiograph for the presence or absence of congestive heart failure and its specific radiographic findings.

RESULTS

The expert panel diagnosed congestive heart failure in 19% (9 of 48) of study patients and in 23% (8 of 35) of controls (P = .65). When present, congestive heart failure was mild to moderate in severity in both the study and control groups (P = 1.00). There was a significant difference in the expert panel agreement between the attending versus the resident interpretation (65% versus 35%, P = .008), for the study group. This resulted in fair agreement (kappa = 0.29) between the expert panel and the attending interpretation and no agreement (kappa = -0.29) between the expert panel and the resident interpretation. In contrast, the expert panel agreed with the joint resident/attending interpretation in 83% (29 of 35) of controls, yielding substantial agreement (kappa = 0.72).

CONCLUSION

Interpretation of chest radiographs for congestive heart failure by radiology residents has a low error rate. The majority of chest radiographs with discrepant resident and attending interpretations were portable films of female patients with subtle radiographic findings of congestive heart failure, and were inherently difficult to interpret.

Academic radiology and the emergency department: does it need changing?

RATIONAL AND OBJECTIVES

The increasing importance of imaging for both diagnosis and management in patient care has resulted in a demand for radiology services 7 days a week, 24 hours a day, especially in the emergency department (ED). We hypothesized the resident preliminary reports were better than generalist radiology interpretations, although inferior to subspecialty interpretations.

MATERIALS AND METHODS

Total radiology volume through our Level I pediatric and adult academic trauma ED was obtained from the radiology information system. We conducted a literature search for error and discordant rates between radiologists of varying experience. For a 2-week prospective period, all preliminary reports generated by the residents and final interpretations were collected. Significant changes in the report were tabulated.

RESULTS

The ED requested 72,886 imaging studies in 2004 (16% of the total radiology department volume). In a 2-week period, 12 of 1929 (0.6%) preliminary reports by residents were discordant to the final subspecialty dictation. In the 15 peer-reviewed publications documenting error rates in radiology, the error rate between American Board of Radiology (ABR)-certified radiologists is greater than that between residents and subspecialists in the literature and in our study. However, the perceived error rate by clinicians outside radiology is significantly higher.

CONCLUSION

Sixteen percent of the volume of imaging studies comes through the ED. The residents handle off-hours cases with a radiology-detected error rate below the error rate between ABR-certified radiologists. To decrease the perceived clinician-identified error rate, we need to change how academic radiology handles ED cases.

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.

Cost-effectiveness analysis of weekday and weeknight or weekend shifts for assessment of appendicitis

BACKGROUND

Assessment of appendicitis during a weeknight or weekend shift (after-hours period, AHP) might be more costly and less effective than its assessment on a weekday shift (standard hours period, SHP) because of increased costs (staff premium fees) and perforation risk (longer delays and less experience of fellows).

OBJECTIVES

The objectives were to compare the costs and effectiveness of assessing children with suspected appendicitis who required a laparotomy and had US or CT after-hours with those of assessing children during standard hours, and to evaluate the importance of diagnostic imaging (DI) within the overall costs.

MATERIALS AND METHODS

We retrospectively microcosted resource use within six areas of a tertiary hospital (emergency [ED], diagnostic imaging (DI), surgery, wards, transport, and pathology) in a tertiary hospital. About 41 children (1.8-17 years) in the AHP and 35 (2.9-16 years) in the SHP were evaluated. Work shift effectiveness was measured with a histological score that assessed the severity of appendicitis (non-perforated appendicitis: scores 1-3; perforated appendicitis: score 4).

RESULTS

The SHP was less costly and more effective regardless of whether the calculation included US or CT costs only. For a salary-based fee schedule, 733 US dollars were saved per case of perforated appendicitis averted in the SHP. For a fee-for-service payment schedule, 847 dollars were saved. Within the overall budget, the highest costs were those incurred on the ward for both shifts. The average cost per patient in DI ranged from 2 to 5% of the total costs in both shifts. Most perforation cases were found in the AHP (31.7%, AHP vs. 17.1%, SHP), which resulted in higher ward costs for patients in the AHP.

CONCLUSION

A higher proportion of severe cases was seen in the AHP, which led to its higher costs. As a result, the SHP dominated the AHP, being less costly and more effective regardless of the fee schedule applied. The DI costs contributed little to the overall cost of the assessment of appendicitis.

Radiology residents' on-call interpretation of chest radiographs for pneumonia

RATIONALE AND OBJECTIVES

This study is designed to assess the performance of radiology residents in interpreting emergency department chest radiographs for pneumonia and to characterize chest radiographic findings in patients for which interpretation was amended by an attending radiologist.

MATERIALS AND METHODS

We retrospectively reviewed all amended reports for chest radiographs performed on emergency department patients July 2002-June 2003. Reports preliminarily interpreted by residents and amended by a board-certified staff radiologist for the presence or absence of pneumonia were identified. A panel of three experienced radiologists, blinded to reports, jointly reviewed each chest radiograph. If the panel diagnosed pneumonia, the chest radiograph was evaluated for the projection that best showed the pneumonia, its size and location, and the presence or absence of the following features: increased opacity, air bronchograms, loss of vascular markings, silhouette sign, and linear opacities. The resident's post-graduate year (PGY) training level was noted.

RESULTS

One percent (134/12,600 reports) of chest radiographic reports were amended for the presence or absence of pneumonia. One hundred chest radiographs were available and comprised the series. There were 56 females and 44 males with a mean age of 45 years (range, 1-99 years). The staff radiologist diagnosed pneumonia in 79% (79/100 radiographs). The panel agreed with the staff in 77% (kappa = 0.76) and the resident in 23% (kappa = 0.43). The panel diagnosed pneumonia in 60% (60/100 radiographs) with the following chest radiographic findings: 100% (60/60), increased opacity; 37% (22/60), air bronchograms; 72% (43/60), loss of vascular markings; 40% (24/60), silhouette sign; and 20% (12/60), linear opacities. The pneumonia was right sided in 52% (31/60), left sided in 37% (22/60), and bilateral in 11% (7/60). Right-sided pneumonias were equally distributed among the three lobes, and left-sided pneumonias had a lower-lobe predominance of 77% (17/22). Seventy-five percent (45/60) of pneumonias were segmental or smaller, and 82% (49/60) of chest radiographs showing pneumonia had both posteroanterior and lateral projections. The pneumonia was conspicuous on only one projection in 43% (21/49); the posteroanterior view in 22% (11/49), and the lateral view in 20% (10/49). Eighty-one percent (81/100) of interpreting residents were PGY-3.

CONCLUSION

Interpretation of chest radiographs for pneumonia by PGY-3 residents has a low error rate. Missed pneumonias often were segmental or smaller and conspicuous on only one projection.

The optimal initial management of children with suspected appendicitis: a decision analysis

BACKGROUND/PURPOSE

As abdominal imaging has improved, the use of computed tomography (CT) and ultrasonography (US) for evaluating children with suspected appendicitis has increased. The purpose of this study was to determine the optimal management strategy for evaluating children with suspected appendicitis given the current accuracy of abdominal imaging.

METHODS

Decision analysis was used to evaluate 5 management strategies: discharge, observation, CT, US, and appendectomy. Probabilities and time variables were obtained from publications and a chart review. Each approach was evaluated for its impact on length of stay, hospital charges, cost effectiveness and its capacity to minimize perforation and avoid negative appendectomy (risk-benefit).

RESULTS

Discharge was preferred when the probability of appendicitis was low (<0.09 to <0.47), imaging when in an intermediate range and surgery when high (>0.61 to >0.91). A role for observation was found only when the anticipated time of inpatient observation was brief (<9 hours). Although CT was more expensive than US, CT was more cost effective for preventing negative appendectomy and perforation and achieved a better risk-benefit.

CONCLUSIONS

CT has an important role in the management of suspected appendicitis. Among children with a low or high likelihood of appendicitis, the cost of imaging tests required to prevent the complications of appendicitis is high.

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.