Accuracy and cost- and time-effectiveness of digital clip versus videotapeinterpretation of echocardiograms in patients with valvular disease

Background. Although digital and videotaped images are known to be comparab le for the evaluation of left ventricular function, their relative accuracy for assessment of more complex anatomy is unclear. We sought to compare re ading time, storage costs, and concordance of video and digital interpretat ions across multiple observers and sites. Methods. One hundred one patients with valvular (90 mitral, 48 aortic, 80 t ricuspid) disease were selected prospectively, and studies were stored acco rding to video and standardized digital protocols. The same reviewer interp reted video and digital images independently and at different times with th e use of a standard report form to evaluate 40 items (eg, severity of steno sis or regurgitation, leaflet thickening, and calcification) as normal or m ildly, moderately, or severely abnormal Concordance between modalities was expressed at kappa Major discordance (difference of >1 level of severity) w as ascribed to the modality that gave the lesser severity. CD-ROM was used to store digital data (20:1 lossy compression), and super-VHS video-tape wa s used to store video data The reading time and storage costs for each moda lity were compared Results. Measured parameters were highly concordant (ejection fraction was 52% +/- 13% by both). Major discordance was rare, and lesser values were re ported with digital rather than video interpretation in the categories of a ortic and mitral valve thicken ing (1% to 2%) and severity of mitral regurg itation (2%). Digital reading time was 6.8 +/- 2.4 minutes, 38% shorter tha n with video (11.0 +/- 3.0, range 8 to 22 minutes, P < .001). Compressed di gital studies had an average size of 60 <plus/minus> 14 megabytes (range 26 to 96 megabytes). Storage cost for video was A$0.62 per patient (18 studie s per tape, total cost A$11.20), compared with A$0.31 per patient for digit al storage (8 studies per CD-ROM, total cost A$2.50). Conclusion. Digital and video interpretation were highly concordant; in the few cases of major discordance, the digital scores were lower, perhaps ref lecting undersampling. Use of additional views and longer clips may be indi cated to minimize discordance with video in patients with complex problems. Digital interpretation offers a significant reduction in reading times and the cost of archiving.