Karson T H, Zepp R C, Chandra S, Morehead A, Thomas J D
Department of Cardiology, Cleveland Clinic Foundation, OH 44195, USA.
J Am Soc Echocardiogr. 1996 Nov-Dec;9(6):769-78. doi: 10.1016/s0894-7317(96)90467-8.
A large interobserver and intraobserver variability study was performed comparing both digitally compressed and uncompressed echocardiographic images with the same images recorded onto super-VHS video-cassette tape (the current standard). In a blinded, randomized fashion, 179 observers scored the diagnostic and image quality of 20 pairs of echocardiographic loops representing various pathologic conditions. Overall, the digital images were preferred to the S-VHS images both for image quality and diagnostic content (p < 0.0001) regardless of the background or experience level of the observer. Furthermore, uncompressed digital images and those compressed by the Joint Photographic Experts Group (JPEG) algorithm at ratios of 20:1 were judged equivalent. These findings show that digital compression may be used routinely in echocardiography, resulting in improved image and diagnostic quality over present standards.