OBJECTIVE. The purposeof our studywas to assessthe potentialof thin-sectionmul tiphasichelicalCT in diagnosisandstagingof hilar cholangiocarcinomas. SUBJECTS AND METHODS. IdenticallycollimatedhelicalCT studieswereperformedbefore and during the hepatic artery dominant phase and during the portal vein dominant phase of contrastenhancementin 29 consecutivepatientswith proven hilar cholangiocarcinomas.Dif ferencesin attenuation betweenthetumorandtheliverwerecalculatedin eachcaseby subtract ing the average attenuation of the tumor from that of the liver. A four-point scale termed a â€oe¿ lesion conspicuityscore― was usedto determineratesof tumordetection.CT findingswere correlated with surgically assessed extent of tumor, histologic findings, or both in all cases. RESULTS. Ten (34%) of the 29 hilar cholangiocarcinomas were detectedon unenhanced images.All hilar cholangiocarcinomas (100%) were seenon hepaticartery dominantphase scans,and 25 (86%) of 29 hilar cholangiocarcinomas were seen on portal vein dominant phase scans, regardless of the morphologic appearance. An infiltrating stenotic lesion was found in 17 (59%) of 29 patients, an exophytic hilar lesion was found in 11 patients (38%), and one patient (3%) had an intraluminal polypoid lesion. Mean differences in enhancement between infiltrating stenotic lesions and the liver were significantly greater on hepatic artery dominant phase scans (28 ±10 H) than on portal vein dominant phase scans (10 ±8 H), whereas the mean difference in enhancement between the exophytic lesions and the liver was statisticallygreaterduringtheportalveindominantphase(p < .01). Two of the hilar cholang iocarcinomas were resectableat surgery, and I 8 were not.The overallaccuracyof helicalCT for assessing resectability was 60%. In 10 (56%) of 18 patients, unresectable disease was cor rectlydiagnosedwith helicalCT (sensitivity, 56%). Eight (44%) of I 8 patientsconsideredto have resectable tumors with helical CT had unresectable tumors at surgery. A resectable Ut mor was correctly diagnosed in two patients with helical CT. CONCLUSION.MultiphasichelicalCT canbe usedto detectandclassifyhilar cholang iocarcinomas. However,theexactproximaltumorextentalongbile ductstendsto be underes timated with helical CT; therefore, helical CT is inaccurate for determining resectability.H ilar cholangiocarcinomas are typi cally small, slow-growing, locally invasive tumors that have a dismal prognosis ifleft untreated, witha meansurvival of approximately 3 months after initial presen tation [1â€"7]. The anatomic location of hilar cholangiocarcinoma makesresectiondifficult [7]. Surgical exploration of these patients should be undertaken only when preoperative examination has shown a potential for curative resection because the risks of palliative surgery for malignant obstructive jaundice are high, with surgical mortality rates of 20â€"30% [8,9]. Accordingly, preoperative assessment of resec tability of hilar cholangiocarcinoma has in creased in importance in recent years because percutaneous and endoscopic p...

Background: Increasing attention is focused on polyp-related features that may contribute to the operator-dependent nature of colonoscopy. Few data on polyps are available from high-yield colonoscopies, which may serve as a benchmark for quality control. Objectives: Describe regional distribution, histology, size and shape of polyps, and the influence of patient age and gender, in colonoscopies performed by a colonoscopist with high lesion detection rate. Methods: Analysis of 698 consecutive patients with diagnostic, screening or surveillance colonoscopies. Results: In 704 colonoscopies, 1908 polyps were removed (360 were protruded and 1548 flat; 1313 were hyperplastic, 562 adenomas, 5 serrated adenomas and 8 mixed). There were 232 adenomas in female patients and 343 in male patients; 39% of the adenomas were protruded and 61% were flat. The peak adenoma detection rate (ADR) was 51% in patients beyond age 79 years. Men older than 49 years had a higher ADR than women. In men and women, respectively: 40% and 32% of adenomas were in the right colon, 31% and 22% were in the transverse colon, and 30% and 47% were in the left colon. Beyond age 59 years, the majority of adenomas were in the proximal colon. Conclusions: An excess of adenomas in the proximal colon started at age 60 and this was more pronounced in men than in women. In all colonic regions, the majority of adenomas had a shape that was flat and smaller than 6 mm.