Sung Min-Mo, Kim Hee-Joung, Yoo Sun Kook, Choi Byoung-Wook, Nam Ji-Eun, Kim Hye-Sung, Lee Jae-Hoon, Yoo Hyung-Sik
BK21 Project for Medical Sciences, Yonsei University, Seoul, Korea.
J Digit Imaging. 2002 Jun;15(2):78-83. doi: 10.1007/s10278-002-0007-6. Epub 2002 Sep 26.
The efficient compression of radiographic images is of importance for improved storage and network utilization in support of picture archiving and communication systems (PACS) applications. The DICOM Working Group 4 adopted JPEG2000 as an additional compression standard in Supplement 61 over the existing JPEG. The wavelet-based JPEG2000 can achieve higher compression ratios with less distortion than the Discrete Cosine Transform (DCT)-based JPEG algorithm. However, the degradation of JPEG2000-compressed computed radiography (CR) chest images has not been tested comprehensively clinically. The authors evaluated the diagnostic quality of JPEG2000-compressed CR chest images with compression ratios from 5:1 to 200:1. An ROC (receiver operating characteristic analysis) and t test were performed to ascertain clinical performance using the JPEG2000-compressed images. The authors found that compression ratios as high as 20:1 can be utilized without affecting lesion detectability. Significant differences between the original and the compressed CR images were not recognized up to compression ratio of 50:1 within a confidence level of 99%.
射线图像的高效压缩对于改善存储和网络利用以支持图像存档与通信系统（PACS）应用至关重要。DICOM工作组4在补充61中采用JPEG2000作为现有JPEG之外的另一种压缩标准。基于小波的JPEG2000与基于离散余弦变换（DCT）的JPEG算法相比，能够以更低的失真实现更高的压缩比。然而，JPEG2000压缩的计算机X线摄影（CR）胸部图像的质量下降尚未在临床上进行全面测试。作者评估了压缩比从5:1到200:1的JPEG2000压缩CR胸部图像的诊断质量。进行了ROC（接受者操作特征分析）和t检验，以确定使用JPEG2000压缩图像的临床性能。作者发现，高达20:1的压缩比可以在不影响病变可检测性的情况下使用。在99%的置信水平内，压缩比达到50:1时，原始CR图像和压缩CR图像之间未发现显著差异。
