ABSTRACT
PURPOSE: To determine the usefulness of compression standard JPEG2000 for compression of mammographic images. MATERIALS AND METHODS: Image of a mammographic phantom was compressed using JPEG2000 at ratios of 10:1, 20:1, 30:1, 40:1, 50:1 and 60:1. The sizes of the images were compared, and scores were recorded by counting the numbers of fibers, groups of specks and masses seen in each phantom image. More than four fibers, three groups of specks and three masses and a total score of 10 were considered acceptable. RESULTS: The size of a DICOM image was 17,042 KB, a TIFF image was 8,324 KB, the original JPEG image was 1,506 KB and the most compressed image (50:1) above an acceptable total score of 10 was 43 KB. In each category, the compression image of fiber was acceptable up to compression ratio of 50:1 (score of 5), groups of specks was acceptable up to 60:1 (score of 3) and mass was acceptable up to 50:1 (score of 3.5). The total score, which was acquired by adding up the individual scores of all three categories, for a compression ratio of 50:1 was 12 and was acceptable, but the total score for 60:1 was 8 and was not acceptable. CONCLUSION: The compression standard JPEG2000 is an efficient means for compressing mammographic images at high ratios without compromising diagnostic value.
Subject(s)
Data CompressionABSTRACT
The laparoscopic cholecystectomy has been rapidly accepted as the standard treatment for gallbladder stones because its minimally invasive nature offers a significant advantage over an open cholecystectomy in terms of postoperative morbidity & recovery. The endoscopic sphinterotomy has become the primary treatment for common bile duct stones, yielding a duct clearance rate of approximately 90%. The laparoscopic cholecystectomy combined with the preoperative endoscopic sphinterotomy is becoming more widely employed as a therapeutic option for the management of gallbladder stones & common bile-duct stones. The authors retrospectively analyzed 71 patients who had been treated by an open cholecystectomy and a common bile-duct exploration (group A) and 35 patients who had been treated by a laparoscopic cholecystectomy plus endoscopic sphinterotomy (group B) at the Department of Surgery, Jungang Gil Hospital, from March 1993 to January 1996. The diagnotic procedures performed were ultrasonography ERC and DISIDA scan, and abdominal computed tomography. Intraoperative cholangiograms were successfully performed in 59 cases from group A and in 5 cases from group B. Successful duct clearance was achieved in 87.3% of the group A cases and in 87.5% of the group B cases. The operation time, the postoperative hospital stay, and postoperative complications were significantly lower for group B than for group A. The major postoperative complication was wound pain & infection for both groups. We conclude that in comparison with group A, group B appeared to have a similar clearance rate, a much lower morbidity, a shorter hospital stay, an earlier return to working fitness, and a better cosmetic result.