Colorectal neoplasia: performance characteristics of CT colonography for detection in 300 patients.

PURPOSE: To determine the sensitivity and specificity of computed tomographic (CT) colonography for colorectal polyp and cancer detection by using colonoscopy as the reference standard. MATERIALS AND METHODS: Three hundred patients underwent CT colonography followed by standard colonoscopy. Bowel preparation consisted of magnesium citrate and polyethylene glycol. After colonic air insufflation, patients underwent scanning in the supine and prone positions with 3-mm collimation during a single breath hold. The transverse CT images, sagittal and coronal reformations, and three-dimensional endoluminal images were interpreted by two radiologists independently, and then a consensus reading was performed. CT colonographic findings were correlated with standard colonoscopic and histologic findings. RESULTS: The overall sensitivity and specificity of CT colonography for polyp detection were 90.1% (164 of 182) and 72.0% (85 of 118), respectively. By using direct polyp matching, the overall sensitivity was 69.7% (365 of 524). The sensitivity was 90% (74 of 82) for the detection of polyps 10 mm or larger, 80.1% (113 of 141) for polyps 5.0-9.9 mm, and 59.1% (178 of 301) for polyps smaller than 5 mm. The sensitivity was 94% (64 of 68) for the detection of adenomas 10 mm or larger, 82% (72 of 88) for adenomas 5.0-9.9 mm, and 66.9% (95 of 142) for adenomas smaller than 5 mm. CT colonography was used to identify all eight carcinomas. CONCLUSION: CT colonography has excellent sensitivity for the detection of clinically important colorectal polyps and cancer.

The usefulness of glucagon hydrochloride for colonic distention in CT colonography.

OBJECTIVE: The purpose of this study was to compare colonic distention with and without glucagon hydrochloride during CT colonography. SUBJECTS AND METHODS: CT colonography using single breath-hold, thin-section helical technique was performed on 60 patients who were in the supine and prone positions. Magnesium citrate and polyethylene glycol were used for bowel preparation. Colonic air insufflation averaged 30 bulb compressions. Thirty-three patients received IV glucagon (1 mg), and 27 patients did not. The colon was divided into eight segments, and the adequacy of the distention of each segment was evaluated. Overall colonic distention scores, defined as the number of inadequately distended segments (0-8), were recorded for the supine, prone, and combined positions. In the combined position, inadequate distention was defined as identical segments that were inadequately distended in both positions. RESULTS: A total of 960 segments were evaluated: 528 segments in the glucagon group and 432 segments in the nonglucagon group. In the glucagon group, 444 segments (84.1%) were adequately distended. In the nonglucagon group, 365 segments (84.5%) were adequately distended. The median and range for overall colonic distention scores in the supine, prone, and combined positions were 1 (0-3), 1 (0-3), and 0 (0), respectively, for the glucagon group and 1 (0-6), 1 (0-6), and 0 (0-1), respectively, for the nonglucagon group. We found no statistically significant difference in overall colonic distention between the glucagon group and the nonglucagon group for the supine (p = .84), prone (p = .15), or combined (p = .28) positions. CONCLUSION: Glucagon administration before CT colonography does not improve colonic distention.

Static load response of the heels of SACH feet.

Excessive heel hardness in the prosthetic foot is a frequent problem that may contribute to decreased function in the above knee and below knee amputee. Optimal mechanical characteristics of the SACH (solid ankle cushion heel) foot have not been defined. In an effort to characterize the mechanical properties of the heels of these feet, we performed static load-deformation tests on the heels of SACH feet at stimulated heelstrike. These data were interpreted using least squares fitting of the natural logarithms of the load-deformation data. Statistical comparison of these data revealed no significant difference in the static response of the "medium" and "regular" grades of foot. A difference at the 1% level of confidence was found between the "soft" grade and the two firmer grades. Consistency within a grade of foot was quite good. Comparison of feet from another manufacturer revealed no difference in static response, suggesting consistency in static performance among manufactures. It was our clinical impression that all grades of SACH heels are too stiff.