Evaluation of the effect of varying MPEG-2 compression ratios on digital coronary angiographic assessment of stenosis severity.
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.
Okura
Yasuhiko
Y
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
Matsumura
Yasushi
Y
Hidaka
Kuniyuki
K
Yokoyama
Hiromichi
H
Inada
Hiroshi
H
Harauchi
Hajime
H
Kou
Hiroko
H
Inamura
Kiyonari
K
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