LOSSY-(15 1)-JPEG-COMPRESSION OF DIGITAL CORONARY ANGIOGRAMS DOES NOTLIMIT DETECTION OF SUBTLE MORPHOLOGICAL FEATURES/

Background Development of the ''all-digital'' cardiac catheterization laboratory has been slowed by substantial computer archival and transf er requirements. Lossy data compression reduces this burden but create s irreversible changes in images, potentially impairing detection of c linically important angiographic features. Methods and Results Fifty i mage sequences from 31 interventional procedures were viewed both in t he original (uncompressed) state and after 15:1 lossy Joint Photograph ic Expert's Group (JPEG) compression. Experienced angiographers identi fied dissections, suspected thrombi, and coronary stents, and their re sults were compared with those from a consensus panel that served as a ''gold standard.'' The panel and the individual observers reviewed th e same image sequences 4 months after the first session to determine i ntraobserver variability. Intraobserver agreement for original images was not significantly different from that for compressed images (89.8% versus 89.5% for 600 pairs of observations in each group). Agreement of individual observers with the consensus panel was not significantly different for original images from that for compressed images (87.6% versus 87.3%; CIs for the difference, -4.0%, 4.0%). Subgroup analysis for each observer and for each detection task (dissection, suspected t hrombus, and stent) revealed no significant difference in agreement. C onclusions The identification of dissections, thrombi, and coronary st ents is not substantially impaired by the application of 15:1 lossy JP EG compression to digital coronary angiograms. These data suggest that digital angiographic images compressed in this manner are acceptable for clinical decisionmaking.