Determining optimal medical image compression: psychometric and image distortion analysis
Determining optimal medical image compression: psychometric and image distortion analysis
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DOI：
10.1186/1471-2342-12-24
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发表时间：
2012-07-31
影响因子：
2.7
通讯作者：
Flint, Alexander C.
中科院分区：
文献类型：
--
作者：
Flint, Alexander C.
背景资料：网络上的存储问题和带宽导致需要最佳压缩医学成像文件，同时保持临床图像质量不受影响。确定多种模态的临床可接受医学图像压缩范围（CT、MR和XR），我们使用医师阅片器对图像失真阈值进行了心理测量分析，并且还通过不同程度的compression.Results:当要求医师阅片师确定压缩阈值时，超过该阈值的图像在临床上会受损，平均图像失真阈值为JPEG Q值23.1 +/- 7.0。在受试者-操作者特征（ROC）图分析中，在Q = 50和Q = 95之间的任何压缩水平下，压缩图像都无法可靠地与原始图像区分开。低于此范围，一些读者能够区分压缩图像和原始图像，但这种区分的高灵敏度和特异性仅在测试的最低JPEG Q值（Q = 5）时遇到。通过对减影图像对中直接测量的图像失真大小的分析表明，在心理测量学确定的两个阈值范围内，JPEG Q值与图像失真度之间的关系呈向上的拐点（大约Q = 25至Q = 50），75%的图像失真发生在Q = 50至Q = 1之间。结论：可以将有损JPEG压缩应用于医学图像，而不损害临床图像质量。JPEG Q值为50或更高（约对应于15：1或更低的压缩比）的适度压缩可应用于医学图像，同时使图像与原始图像无法区分。
Background: Storage issues and bandwidth over networks have led to a need to optimally compress medical imaging files while leaving clinical image quality uncompromised.Methods: To determine the range of clinically acceptable medical image compression across multiple modalities (CT, MR, and XR), we performed psychometric analysis of image distortion thresholds using physician readers and also performed subtraction analysis of medical image distortion by varying degrees of compression.Results: When physician readers were asked to determine the threshold of compression beyond which images were clinically compromised, the mean image distortion threshold was a JPEG Q value of 23.1 +/- 7.0. In Receiver-Operator Characteristics (ROC) plot analysis, compressed images could not be reliably distinguished from original images at any compression level between Q = 50 and Q = 95. Below this range, some readers were able to discriminate the compressed and original images, but high sensitivity and specificity for this discrimination was only encountered at the lowest JPEG Q value tested (Q = 5). Analysis of directly measured magnitude of image distortion from subtracted image pairs showed that the relationship between JPEG Q value and degree of image distortion underwent an upward inflection in the region of the two thresholds determined psychometrically (approximately Q = 25 to Q = 50), with 75 % of the image distortion occurring between Q = 50 and Q = 1.Conclusion: It is possible to apply lossy JPEG compression to medical images without compromise of clinical image quality. Modest degrees of compression, with a JPEG Q value of 50 or higher (corresponding approximately to a compression ratio of 15:1 or less), can be applied to medical images while leaving the images indistinguishable from the original.