title: Evaluation of the effect of varying MPEG-2 compression ratios on digital coronary angiographic assessment of stenosis severity.
abstract: The purpose of this study is to evaluate the influence of MPEG-2 compression scheme on coronary angiography and to search the highest compression ratio at which no significant effect to accuracy of assessment of stenosis severity occurs. Forty-Four digital cine angiographies were used. Three cardiologists participated in a subjective study in which they read both uncompressed images and compressed images. Furthermore, an objective study was carried out to measure vessel stenosis ratio by using software. The influence of compression was evaluated by kappa statistics in case of subjective study and by both systematic error and random error in case of objective study. Kappa statistics between uncompressed image and compressed image at a ratio of 80:1 was significantly lower than that of other compression ratios such as 40:1. Similar results were obtained in objective evaluation. In this report, the authors provide the baseline for further studies on observer performance for motion images.
authors.affiliation: Graduate School of Medicine, Course of Health Sciences, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan. ookura@sahs.med.osaka-u.ac.jp
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Okura
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsumura
authors.forename: Kuniyuki
authors.initials: K
authors.lastname: Hidaka
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inada
authors.forename: Hajime
authors.initials: H
authors.lastname: Harauchi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kou
authors.forename: Kiyonari
authors.initials: K
authors.lastname: Inamura
mesh_terms: D017023:Coronary Angiography / Q000379:methods* / Q000592:standards; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000592:standards; D012984:Software