Percutaneous transhepatic balloon dilatation of benign biliary strictures.

Between February 1981 and June 1984, 15 patients with benign biliary strictures were treated with percutaneous transhepatic balloon dilatation. Three of these patients had received liver transplants. The treatment began with a course of balloon dilatation therapy, after which a stent catheter was left across the stricture. Six weeks later, after duct patency had been shown by cholangiography, the stent catheter was removed from all but two patients, both of whom had intrahepatic sclerosing cholangitis. After this procedure, six patients (40%), including two liver-transplant patients, were stricture-free after one treatment for periods ranging from 27 to 56 months, and were considered to be treatment successes. Nine patients (60%) suffered stricture recurrences. In eight of these patients, the stricture was heralded by symptoms of either cholangitis or jaundice; in one patient, who was on permanent catheter drainage, the stricture was discovered only on follow-up cholangiography. All successfully treated patients had only one stricture, while all patients with more than one stricture suffered recurrences. Our data also suggest a greater responsiveness for anastomotic strictures than for non-anastomotic strictures. Of the patients with recurrences, five had symptom-free intervals of 23 months or more (up to 31 months). The fact that strictures recurred after such long periods of time underscores the importance of long-term follow-up. In view of the number of patients helped, the favorable experience with post-liver-transplantation strictures, and the lack of any major complications in our series, percutaneous biliary balloon dilatation offers a viable alternative to surgical management of benign biliary strictures

Perceived Sufficiency of Full-Field Digital Mammograms With and Without Irreversible Image Data Compression for Comparison with Next-Year Mammograms

Problems associated with the large file sizes of digital mammograms have impeded the integration of digital mammography with picture archiving and communications systems. Digital mammograms irreversibly compressed by the novel wavelet Access Over Network (AON) compression algorithm were compared with lossless-compressed digital mammograms in a blinded reader study to evaluate the perceived sufficiency of irreversibly compressed images for comparison with next-year mammograms. Fifteen radiologists compared the same 100 digital mammograms in three different comparison modes: lossless-compressed vs 20:1 irreversibly compressed images (mode 1), lossless-compressed vs 40:1 irreversibly compressed images (mode 2), and 20:1 irreversibly compressed images vs 40:1 irreversibly compressed images (mode 3). Compression levels were randomly assigned between monitors. For each mode, the less compressed of the two images was correctly identified no more frequently than would occur by chance if all images were identical in compression. Perceived sufficiency for comparison with next-year mammograms was achieved by 97.37% of the lossless-compressed images and 97.37% of the 20:1 irreversibly compressed images in mode 1, 97.67% of the lossless-compressed images and 97.67% of the 40:1 irreversibly compressed images in mode 2, and 99.33% of the 20:1 irreversibly compressed images and 99.19% of the 40:1 irreversibly compressed images in mode 3. In a random-effect analysis, the irreversibly compressed images were found to be noninferior to the lossless-compressed images. Digital mammograms irreversibly compressed by the wavelet AON compression algorithm were as frequently judged sufficient for comparison with next-year mammograms as lossless-compressed digital mammograms