SUBJECTS AND METHODS. Thirty-eight patients (23 men, 15 women) with clinically suspected rectal carcinoma underwent 3-T MRI. Coronal, axial, and sagittal T2-weighted sequences with and without fat suppression; axial T1-weighted spin-echo sequences; axial T1-weighted gradient-echo sequences with and without fat suppression; oblique 2D MR hydrography; and 3D fat-suppressed dynamic contrast-enhanced MRI were performed. Image quality with these sequences was evaluated by three radiologists experienced in body MRI. The significance of difference in results with the sequences was tested. The manner in which MRI staging and feasibility of sphincter-sparing surgery agreed with operative and pathologic findings was evaluated with kappa statistics.

RESULTS. Rectal carcinoma was identified on MRI and confirmed histologically in all 38 patients. MRI findings were correctly predictive of T category in 35 cases (accuracy, 92.1%). In 31 (96.9%) of 32 resectable cases,sphincter-sparing surgical approaches were accurately chosen on the basis of MRI findings. Among the 11 sequences, 3D fat-suppressed dynamic contrast-enhanced MRI best delineated tumor margins. Coronal and axial T2-weighted images also well depicted tumor margins with minimal artifact. T2-weighted images were superior to unenhanced T1-weighted images.

CONCLUSION. MRI of rectal cancer at 3 T is accurate for prediction of T category and the feasibility of sphincter-sparing surgery. The best images were obtained with coronal, sagittal, and axial T2-weighted sequences and 3D fat-suppressed dynamic contrast-enhanced MRI.

MATERIALS AND METHODS. The study included phantoms (23 phantom objects) and patients (16 polyps). Measurement with sliding calipers served as the reference for the phantom data. The mean of two independent colonoscopic measurements was the reference for the polyps. The automated measurement was developed for a computer-aided detection scheme, and the size of any detected object was obtained from measurement of its largest diameter. The automated measurement was compared with manual 2D and 3D measurements by two experienced observers.

RESULTS. For phantom data, the measurement variability of the automated method was significantly less than that of the two observers (p < 0.05), except for the 3D measurement by observer 1, as follows: automated, 0.86 mm; observer 1, 1.76 mm (2D), 0.96 (3D); observer 2, 1.34 mm (2D), 1.45 mm (3D). The variability of the automated method did not differ significantly from that of manual methods in measurement with patient data. The automated method had a systematic error for phantom data (1.9 mm).

CONCLUSION. For phantoms, the automated method has less measurement variability than manual 2D and 3D techniques. For true polyps, the measurement variability of the automated method is comparable with that of manual methods. The automated method does not suffer from intraobserver variability. Because systematic error can be calibrated, automated size measurement may contribute to a practical evaluation strategy.

CONCLUSION. Jejunal diverticula have characteristic findings on CT, appearing as discrete round or ovoid, contrast-, fluid-, or air-containing structures outside the expected lumen of the small bowel, with a smooth, barely discernible wall and no recognizable small-bowel folds. Not infrequently, these structures are seen to communicate directly with an adjoining small-bowel loop, a feature best recognized by scrolling the images. Our experience suggests that jejunal diverticulosis can often be recognized on the basis of the characteristic CT features of this condition.

MATERIALS AND METHODS. Mathematic and Markov models were used to assess the mean number of CTC procedures per MDCT scanner per day (expressed as CTC/MDCT/day) necessary for both the startup and steady-state phases of a nationwide screening effort. Plausible ranges were applied to a number of variables in the sensitivity analysis. The number of existing CT scanners in the United States was based on 2006 estimates.

RESULTS. At baseline analysis, assuming gradual increases in compliance, CTC penetrance (percentage of screening-compliant population who would opt for CTC), and MDCT capacity, a total of 37,227,541 adults would need to undergo CTC screening over a 10-year startup period, corresponding to 1.2–1.6 CTC/MDCT/day. Assuming a 5-year routine screening interval between the ages of 50 and 80 years, the number of CTC studies needed to be performed in the steady-state period is 1.2 CTC/MDCT/day. These estimates were sensitive to variations in compliance, MDCT capacity, population size, interval for the startup phase, and the routine CTC screening interval.

CONCLUSION. CT capacity in the United States appears to be adequate for handling the potential demand related to mass population screening with CTC, even without assuming a specific CTC-driven increase in MDCT supply.

MATERIALS AND METHODS. A search of our radiology database revealed the cases of 234 women who underwent surgical resection for pelvic endometriosis with associated intestinal surgery for intestinal endometriosis. We retrospectively evaluated all preoperative DCBE images for the presence of bowel endometriosis and the number, site (rectum, sigmoid, cecum), and size of the lesions. The radiographic findings at DCBE were retrospectively correlated with those at surgical pathologic examination.

RESULTS. DCBE revealed 211 intestinal lesions of bowel endometriosis in 168 (71.8%) of 234 patients with pelvic endometriosis clinically enrolled. Forty (23.8%) of the 168 women had more than one endometriotic bowel nodule (two nodules in 37 cases, three in three cases). Laparoscopy revealed 233 intestinal lesions in 174 (74.3%) of the patients. Fifty-four (31.0%) of 174 women had more than one endometriotic bowel nodule (two nodules in 49 cases, three in five cases). There was 100% correlation between the DCBE and histologic findings as far as site and size of the lesions were concerned. DCBE had a sensitivity of 88.4%, specificity of 93.0%, positive predictive value of 97.5%, negative predictive of 71.0%, and accuracy of 89.5% in the identification of bowel endometriosis.

CONCLUSION. DCBE is helpful in discerning bowel wall involvement in endometriosis, enabling proper surgical planning. DCBE also appears to have a role in the management of endometriosis.