Baker W A, Hearne S E, Spero L A, Morris K G, Harrington R A, Sketch M H, Behar V S, Kong Y, Peter R H, Bashore T M, Harrison J K, Cusma J T
Duke University Medical Center, Department of Medicine, Durham, NC 27710, USA.
Circulation. 1997 Aug 19;96(4):1157-64. doi: 10.1161/01.cir.96.4.1157.
Development of the "all-digital" cardiac catheterization laboratory has been slowed by substantial computer archival and transfer requirements. Lossy data compression reduces this burden but creates irreversible changes in images, potentially impairing detection of clinically important angiographic features.
Fifty image sequences from 31 interventional procedures were viewed both in the original (uncompressed) state and after 15:1 lossy Joint Photographic Expert's Group (JPEG) compression. Experienced angiographers identified dissections, suspected thrombi, and coronary stents, and their results were compared with those from a consensus panel that served as a "gold standard." The panel and the individual observers reviewed the same image sequences 4 months after the first session to determine intraobserver 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 thrombus, and stent) revealed no significant difference in agreement.
The identification of dissections, thrombi, and coronary stents is not substantially impaired by the application of 15:1 lossy JPEG compression to digital coronary angiograms. These data suggest that digital angiographic images compressed in this manner are acceptable for clinical decision-making.
“全数字化”心导管实验室的发展因大量的计算机存档和传输需求而放缓。有损数据压缩减轻了这一负担，但会造成图像的不可逆变化，可能会影响对临床重要血管造影特征的检测。
来自31例介入手术的50个图像序列在原始（未压缩）状态下以及经过15:1的有损联合图像专家组（JPEG）压缩后进行观察。经验丰富的血管造影师识别夹层、可疑血栓和冠状动脉支架，并将其结果与作为“金标准”的共识小组的结果进行比较。该小组和个体观察者在第一次观察后的4个月对相同的图像序列进行复查，以确定观察者内部的变异性。原始图像的观察者内部一致性与压缩图像的观察者内部一致性无显著差异（每组600对观察结果中，分别为89.8%和89.5%）。个体观察者与共识小组的一致性在原始图像和压缩图像之间无显著差异（分别为87.6%和87.3%；差异的95%置信区间为-4.0%，4.0%）。对每位观察者和每项检测任务（夹层、可疑血栓和支架）的亚组分析显示一致性无显著差异。
对数字冠状动脉造影应用15:1的有损JPEG压缩不会显著影响夹层、血栓和冠状动脉支架的识别。这些数据表明，以这种方式压缩的数字血管造影图像可用于临床决策。
