Penedo Mónica, Lado María J, Tahoces Pablo G, Souto Miguel, Vidal Juan J
Laboratory of Medical Imaging, Unidad de Medicina y Cirugía Experimental, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
IEEE Trans Inf Technol Biomed. 2006 Apr;10(2):354-61. doi: 10.1109/titb.2005.864381.
The functionalities of the JPEG2000 standard have led to its incorporation into digital imaging and communications in medicine (DICOM), which makes this compression method available for medical systems. In this study, we evaluated the compression of mammographic images with JPEG2000 (16 : 1, 20 : 1, 40 : 1, 60.4 : 1, 80: 1, and 106 : 1) for applications with a computer-aided detection (CAD) system for clusters of microcalcifications. Jackknife free-response receiver operating characteristic (JAFROC) analysis indicated that differences in the detection of clusters of microcalcifications were not statistically significant for uncompressed versus 16: 1 (T = -0.7780; p = 0.4370), 20 : 1 (T = 1.0361; p = 0.3007), and 40 : 1 (T = 1.6966; p = 0.0904); and statistically significant for uncompressed versus 60.4 : 1 (T = 5.8883; p < 0.008), 80 : 1 (T = 7.8414; p < 0.008), and 106 : 1 (T = 17.5034; p = < 0.008). Although there is a small difference in peak signal-to-noise ratio (PSNR) between compression ratios, the true-positive (TP) and false-positive (FP) rates, and the free-response receiver operating characteristic (FROC), figure of merit values considerably decreased from a 60 : 1 compression ratio. The performance of the CAD system is significantly reduced when using images compressed at ratios greater than 40 : 1 with JPEG2000 compared to uncompressed images. Mammographic images compressed up to 20 : 1 provide a percentage of correct detections by our CAD system similar to uncompressed images, regardless of the characteristics of the cluster. Further investigation is required to determine how JPEG2000 affects the detectability of clusters of microcalcifications as a function of their characteristics.
JPEG2000标准的功能使其被纳入医学数字成像和通信（DICOM）中，这使得这种压缩方法可用于医疗系统。在本研究中，我们评估了使用JPEG2000（16:1、20:1、40:1、60.4:1、80:1和106:1）对乳腺钼靶图像进行压缩，以用于微钙化簇的计算机辅助检测（CAD）系统。留一法自由响应接收器操作特性（JAFROC）分析表明，对于未压缩图像与16:1（T = -0.7780；p = 0.4370）、20:1（T = 1.0361；p = 0.3007）和40:1（T = 1.6966；p = 0.0904）的图像，微钙化簇检测的差异无统计学意义；而对于未压缩图像与60.4:1（T = 5.8883；p < 0.008）、80:1（T = 7.8414；p < 0.008）和106:1（T = 17.5034；p = < 0.008）的图像，差异有统计学意义。尽管压缩比之间的峰值信噪比（PSNR）存在微小差异，但真阳性（TP）和假阳性（FP）率以及自由响应接收器操作特性（FROC）品质因数在压缩比达到60:1时显著下降。与未压缩图像相比，当使用JPEG2000以大于40:1的比例压缩的图像时，CAD系统的性能显著降低。无论微钙化簇的特征如何，压缩至20:1的乳腺钼靶图像由我们的CAD系统提供的正确检测百分比与未压缩图像相似。需要进一步研究以确定JPEG2000如何根据微钙化簇的特征影响其可检测性。
