Analysis of air contrast barium enema, computed tomographic colonography, and colonoscopy: prospective comparison.

BACKGROUND: The usefulness of currently available colon imaging tests, including air contrast barium enema (ACBE), computed tomographic colonography (CTC), and colonoscopy, to detect colon polyps and cancers is uncertain. We aimed to assess the sensitivity of these three imaging tests. METHODS: Patients with faecal occult blood, haematochezia, iron-deficiency anaemia, or a family history of colon cancer underwent three separate colon-imaging studies--ACBE, followed 7-14 days later by CTC and colonoscopy on the same day. The primary outcome was detection of colonic polyps and cancers. Outcomes were assessed by building an aggregate view of the colon, taking into account results of all three tests. FINDINGS: 614 patients completed all three imaging tests. When analysed on a per-patient basis, for lesions 10 mm or larger in size (n=63), the sensitivity of ACBE was 48% (95% CI 35-61), CTC 59% (46-71, p=0.1083 for CTC vs ACBE), and colonoscopy 98% (91-100, p<0.0001 for colonoscopy vs CTC). For lesions 6-9 mm in size (n=116), sensitivity was 35% for ACBE (27-45), 51% for CTC (41-60, p=0.0080 for CTC vs ACBE), and 99% for colonoscopy (95-100, p<0.0001 for colonoscopy vs CTC). For lesions of 10 mm or larger in size, the specificity was greater for colonoscopy (0.996) than for either ACBE (0.90) or CTC (0.96) and declined for ACBE and CTC when smaller lesions were considered. INTERPRETATION: Colonoscopy was more sensitive than other tests, as currently undertaken, for detection of colonic polyps and cancers. These data have important implications for diagnostic use of colon imaging tests.

Patient experience and preferences toward colon cancer screening: a comparison of virtual colonoscopy and conventional colonoscopy.

BACKGROUND: Virtual colonoscopy has excellent sensitivity for the detection of cancer and polyps greater than 1 cm in diameter. For virtual colonoscopy to succeed as a screening test for colorectal neoplasia, it must be well tolerated and accepted by patients. Patients' experiences with virtual colonoscopy and conventional colonoscopy were assessed and compared. METHODS: Patients referred to the GI clinic for colonoscopy for any indication were recruited to undergo virtual colonoscopy before conventional colonoscopy. Patients were asked to complete a questionnaire twice: after virtual colonoscopy and after completing both tests. Three variables, overall pain, discomfort, and lack of respect, were assessed by using a 7-point Liken scale with higher scores denoting a worse experience. Patients' preferences for virtual colonoscopy versus conventional colonoscopy were determined with a time tradeoff technique. To verify response stability, patients were asked to return an additional questionnaire by mail at 24 hours. RESULTS: Two hundred ninety-five patients completed the questionnaire immediately after the procedures, and 83 patients completed the questionnaire at 24 hours. At both 0 and 24 hours, patients reported more pain, discomfort, and less respect after virtual colonoscopy than conventional colonoscopy (p < 0.01). The overall agreement (Kappa statistic) between times 0 and 24 hours was fair. Patients reported that they preferred conventional colonoscopy and would wait longer for conventional colonoscopy (mean = 4.9 weeks) than undergo a virtual colonoscopy (p < 0.01). CONCLUSIONS: Patients tolerate both virtual colonoscopy and conventional colonoscopy, although they report more pain, discomfort, and less respect undergoing virtual colonoscopy. Efforts to improve patient experience during virtual colonoscopy need to be investigated.

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.

Inflammatory bowel disease in the elderly. Practical treatment guidelines.

Although Crohn's disease and ulcerative colitis were initially described in young adults, it has become increasingly apparent that inflammatory bowel disease (IBD) affects the elderly, with the new onset of disease occurring well into the seventh and eighth decades of life. The diagnosis of IBD in the elderly may be difficult because it can be easily confused with infectious, ischaemic and drug-related processes, as well as with diverticulitis and carcinoma. Although medical treatment for IBD is similar in the young and the elderly, consideration must be given to comorbid illnesses in the older patient. Topical agents should be used as first-line therapy for patients with distal colonic disease. In patients with more proximal involvement, oral mesalazine or sulfasalazine should be used for maintenance therapy, with corticosteroids being reserved for patients with active disease. Metronidazole is particularly efficacious in patients with colonic Crohn's disease. Finally, immunomodulators can be helpful in patients who are steroid-dependent or refractory to the therapies noted above. This article reviews and outlines practical treatment guidelines for the older patient with IBD.

Corticosteroid-associated complications in elderly Crohn's disease patients.

OBJECTIVES: Although complications occur with long-term steroid usage in elderly Crohn's disease patients, there is little information on their short-term risk. This study was designed to assess that risk. METHOD: We reviewed admissions from 1984 to 1995 and found 115 patients over age 50 yr with a confirmed flare of Crohn's disease. Of this group, 55 patients were treated with steroids. We studied potential complications including hypertension (blood pressure > or = 160/90), hyperglycemia (glucose > 200 mg/dl), hypokalemia (K < 3.5 meq/l), mental status changes, nosocomial infections, and heart failure. RESULTS: The mean age was 67 yr (50-90), and 64% were women. There were no differences in baseline characteristics between patients treated with steroids and those not treated with steroids. The relative risk for developing complications are as follows: hypertension 1.46 (95% confidence interval (CI) = 1.09-1.95), hyperglycemia, 1.53 (95% CI = 0.54-4.32), hypokalemia, 1.59 (95% CI = 1.06-2.37), mental status changes, 7.64 (95% CI = 0.97-60.1), nosocomial infection, 1.09 (95% CI = 0.37-3.18), and congestive heart failure, 1.09 (95% CI = 0.16-7.48). Multivariate analyses adjusting for age, severity index, and number of comorbid conditions demonstrated similar findings to the unadjusted analyses. Analyses stratified by patient age demonstrated a similar risk of steroid associated complications for patients < 65 and > or = 65 yr of age. CONCLUSION: Crohn's disease patients over age 50 yr treated with steroids are at significantly increased risk for developing hypertension and hypokalemia and at increased risk for developing mental status changes, but such steroid-effects were not more pronounced with advancing age.

Cell type-specific gene expression in the Drosophila melanogaster male accessory gland.

The accessory gland of the male Drosophila melanogaster plays a vital role in reproduction. This secretory organ synthesizes products that are transferred to the female and are necessary to elicit the proper physiological and behavioral responses in the female. The accessory gland is composed of two morphologically distinct secretory cell types, the main cells and the secondary cells. Previous studies identified some genes expressed in main cells or in all accessory gland cells. In this paper we use P-element mediated enhancer traps to examine gene expression in the accessory gland. We show that, in addition to genes expressed in main cells only or in all accessory gland secretory cells, there are genes expressed specifically in secondary cells. Each cell type is uniform in the expression of its genes. Our results demonstrate that the two cell types are not only morphologically distinct but also biochemically distinct. We also show that the two cell types differ in their regulation of gene expression in response to mating activity.