Karson T H, Chandra S, Morehead A J, Stewart W J, Nissen S E, Thomas J D
Department of Cardiology, Cleveland Clinic Foundation, USA.
J Am Soc Echocardiogr. 1995 May-Jun;8(3):306-18. doi: 10.1016/s0894-7317(05)80041-0.
Routine echocardiograms are not handled digitally because of enormous storage needs. Image compression techniques can reduce memory requirements, but the impact on diagnostic content is unknown. We studied the effect of an internationally accepted compression algorithm called Joint Photographic Experts Group (JPEG) on digital echocardiographic images. Diagnostic and image quality of JPEG compressed, two-dimensional echocardiograms at ratios ranging from 4:1 to 40:1 was compared with that of uncompressed images both subjectively by a blinded expert panel (540 observations) and objectively by quantitative image-processing parameters (180 images). Accuracy of 432 measurements performed on compressed M-mode and spectral Doppler tracings was determined. Simultaneously acquired videotaped images and their never-compressed digital counterparts were compared quantitatively for image fidelity. This study demonstrates that the JPEG compression algorithm produces little degradation of echocardiographic images at compression ratios of at least 20:1, with less measured distortion than is produced by videotape recording. With JPEG, digital storage and retrieval in routine echocardiography are feasible.
由于存储需求巨大，常规超声心动图未进行数字化处理。图像压缩技术可以降低内存需求，但对诊断内容的影响尚不清楚。我们研究了一种国际认可的名为联合图像专家组（JPEG）的压缩算法对数字超声心动图图像的影响。通过一个盲法专家小组主观地（540次观察）以及通过定量图像处理参数客观地（180幅图像），将压缩比例从4:1到40:1的JPEG压缩二维超声心动图的诊断和图像质量与未压缩图像进行了比较。确定了对压缩的M型和频谱多普勒描记图进行的432次测量的准确性。对同时采集的录像图像及其未压缩的数字对应图像进行了图像保真度的定量比较。这项研究表明，JPEG压缩算法在至少20:1的压缩比例下对超声心动图图像产生的退化很小，测量到的失真比录像记录产生的失真要小。使用JPEG，常规超声心动图中的数字存储和检索是可行的。
