CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography.

OBJECTIVES: To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps. METHODS: Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD. RESULTS: Of seven readers, 86% and 71% achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p < 0.0001) than average AUC in the unaided evaluation (0.781). Per-segment, per-polyp, and per-patient sensitivities for polyps ≥6 mm were significantly higher in both CAD reading paradigms compared with unaided evaluation. Second-read CAD reduced readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively. CONCLUSIONS: CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader. KEY POINTS: • CAD helps radiologists with moderate CTC experience to detect polyps ≥6 mm. • Second and concurrent read CAD increase the radiologist's sensitivity for detecting polyps ≥6 mm. • Second read CAD slightly decreases specificity compared with an unassisted read. • Concurrent read CAD is significantly more time-efficient than second read CAD.

Radiologic evaluation of postoperative gastropericardial fistula.

Laparoscopic Nissen fundoplication is the current standard surgical option for complicated GERD and symptomatic hiatal hernia. Though comparable in safety, short-term efficacy, and patient satisfaction when compared with open operation, laparoscopic Nissen fundoplication has demonstrated shorter hospital stays and recuperative times. Commonly reported complications include gastric or esophageal injury, splenic injury, pneumothorax, bleeding, pneumonia, fever, wound infections, and dysphagia. We present an unusual case of gastropericardial fistula that developed as a late complication of laparoscopic Nissen fundoplication performed 4 years earlier.

Pitfalls in CT diagnosis of appendicitis: pictorial essay.

Despite the high diagnostic accuracy of CT for appendicitis, numerous pitfalls exist that may result in a misdiagnosis. This pictorial review outlines the potential pitfalls in the CT diagnosis of appendicitis that includes atypical position of the appendix and coexisting pathologies. Various mimickers of appendicitis and clinical dilemmas will be highlighted. Upon completion, the reviewer should have an improved ability to recognise appendicitis mimickers and identify equivocal or atypical findings.