Diagnostic Ultrasound for Acute Appendicitis: The Gold Standard.

BACKGROUND: Acute appendicitis may present a diagnostic dilemma. The aim of this study was to review the accuracy of ultrasound in the diagnosis of paediatric acute appendicitis. METHOD: Ultrasound studies performed for investigation of appendicitis during 2015-2021 were retrieved from a tertiary paediatric hospital database and reviewed. Medical records were reviewed to determine operative intervention, further imaging, and final diagnosis. Diagnostic accuracy was assessed by sensitivity, specificity, predictivity, and overall accuracy. All appendicectomy specimens underwent histopathological confirmation. This study was approved by the local Human Research Ethics Committee. RESULTS: A total of 8555 consecutive ultrasound examinations were performed during the study period. Mean patient age was 10.8 years ( ± 3.7). Overall diagnostic accuracy was 96.1% (8221/8555) with a visualisation rate of 91.0%. Sensitivity and specificity were 96.2% (CI 95.3-97.0%) and 96.1% (CI 95.6-96.5%), respectively. When limited to positive/negative scans, sensitivity was 99.6% (CI 99.2-99.8%) and specificity 99.0% (CI 98.7-99.3%). Positive and negative predictive values were 96.9% and 99.9%, respectively. Repeat ultrasound following a non-diagnostic scan led to a definitive diagnosis in 76.1%. Negative appendicectomy rate was 5.5% overall in children who had undergone pre-operative ultrasound (107/1938), and 4.4% when other surgical pathologies were excluded. CONCLUSION: Ultrasound examination provides gold-standard accuracy in the diagnosis of paediatric appendicitis and reduces rates of negative appendicectomy. Given the disadvantages of computed tomography and magnetic resonance imaging, ultrasound should be considered the first-line investigation of choice in the diagnosis of acute appendicitis in children. LEVEL OF EVIDENCE: III.

Randomised controlled trial comparing modified Sano's and narrow band imaging international colorectal endoscopic classifications for colorectal lesions.

AIM: To assess the utility of modified Sano's (MS) vs the narrow band imaging international colorectal endoscopic (NICE) classification in differentiating colorectal polyps. METHODS: Patients undergoing colonoscopy between 2013 and 2015 were enrolled in this trial. Based on the MS or the NICE classifications, patients were randomised for real-time endoscopic diagnosis. This was followed by biopsies, endoscopic or surgical resection. The endoscopic diagnosis was then compared to the final (blinded) histopathology. The primary endpoint was the sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of differentiating neoplastic and non-neoplastic polyps (MS II/IIo / IIIa / IIIb vs I or NICE 1 vs 2/3). The secondary endpoints were "endoscopic resectability" (MS II/IIo/IIIa vs I/IIIb or NICE 2 vs 1/3), NPV for diminutive distal adenomas and prediction of post-polypectomy surveillance intervals. RESULTS: A total of 348 patients were evaluated. The Sn, Sp, PPV and NPV in differentiating neoplastic polyps from non-neoplastic polyps were, 98.9%, 85.7%, 98.2% and 90.9% for MS; and 99.1%, 57.7%, 95.4% and 88.2% for NICE, respectively. The area under the receiver operating characteristic curve (AUC) for MS was 0.92 (95%CI: 0.86-0.98); and AUC for NICE was 0.78 (95%CI: 0.69, 0.88). The Sn, Sp, PPV and NPV in predicting "endoscopic resectability" were 98.9%, 86.1%, 97.8% and 92.5% for MS; and 98.6%, 66.7%, 94.7% and 88.9% for NICE, respectively. The AUC for MS was 0.92 (95%CI: 0.87-0.98); and the AUC for NICE was 0.83 (95%CI: 0.75-0.90). The AUC values were statistically different for both comparisons (P = 0.0165 and P = 0.0420, respectively). The accuracy for diagnosis of sessile serrated adenoma/polyp (SSA/P) with high confidence utilizing MS classification was 93.2%. The differentiation of SSA/P from other lesions achieved Sp, Sn, PPV and NPV of 87.2%, 91.5%, 89.6% and 98.6%, respectively. The NPV for predicting adenomas in diminutive rectosigmoid polyps (n = 150) was 96.6% and 95% with MS and NICE respectively. The calculated accuracy of post-polypectomy surveillance for MS group was 98.2% (167 out of 170) and for NICE group was 92.1% (139 out of 151). CONCLUSION: The MS classification outperformed the NICE classification in differentiating neoplastic polyps and predicting endoscopic resectability. Both classifications met ASGE PIVI thresholds.