IEEE Trans Med Imaging. 2020 Apr;39(4):1064-1072. doi: 10.1109/TMI.2019.2930338. Epub 2019 Sep 16.
Image quality metrics (IQMs) such as root mean square error (RMSE) and structural similarity index (SSIM) are commonly used in the evaluation and optimization of accelerated magnetic resonance imaging (MRI) acquisition and reconstruction strategies. However, it is unknown how well these indices relate to a radiologist's perception of diagnostic image quality. In this study, we compare the image quality scores of five radiologists with the RMSE, SSIM, and other potentially useful IQMs: peak signal to noise ratio (PSNR) multi-scale SSIM (MSSSIM), information-weighted SSIM (IWSSIM), gradient magnitude similarity deviation (GMSD), feature similarity index (FSIM), high dynamic range visible difference predictor (HDRVDP), noise quality metric (NQM), and visual information fidelity (VIF). The comparison uses a database of MR images of the brain and abdomen that have been retrospectively degraded by noise, blurring, undersampling, motion, and wavelet compression for a total of 414 degraded images. A total of 1017 subjective scores were assigned by five radiologists. IQM performance was measured via the Spearman rank order correlation coefficient (SROCC) and statistically significant differences in the residuals of the IQM scores and radiologists' scores were tested. When considering SROCC calculated from combining scores from all radiologists across all image types, RMSE and SSIM had lower SROCC than six of the other IQMs included in the study (VIF, FSIM, NQM, GMSD, IWSSIM, and HDRVDP). In no case did SSIM have a higher SROCC or significantly smaller residuals than RMSE. These results should be considered when choosing an IQM in future imaging studies.
图像质量指标 (IQMs) ，如均方根误差 (RMSE) 和结构相似性指数 (SSIM) ，常用于评估和优化加速磁共振成像 (MRI) 采集和重建策略。然而，这些指标与放射科医生对诊断图像质量的感知之间的关系尚不清楚。在这项研究中，我们将五名放射科医生的图像质量评分与 RMSE 、 SSIM 以及其他潜在有用的 IQMs 进行了比较：峰值信噪比 (PSNR) 多尺度 SSIM (MSSSIM) 、信息加权 SSIM (IWSSIM) 、梯度幅度相似性偏差 (GMSD) 、特征相似性指数 (FSIM) 、高动态范围可见度差异预测器 (HDRVDP) 、噪声质量度量 (NQM) 和视觉信息保真度 (VIF) 。比较使用了一个脑和腹部 MRI 图像数据库，这些图像已经通过噪声、模糊、欠采样、运动和小波压缩进行了回顾性降级，共有 414 张降级图像。五名放射科医生共给出了 1017 个主观评分。通过 Spearman 等级相关系数 (SROCC) 测量 IQM 性能，并对 IQM 评分和放射科医生评分的残差进行了统计学显著差异测试。当考虑到所有图像类型的所有放射科医生的评分组合计算的 SROCC 时，RMSE 和 SSIM 的 SROCC 低于研究中包含的其他六种 IQMs （VIF 、 FSIM 、 NQM 、 GMSD 、 IWSSIM 和 HDRVDP ）。在任何情况下，SSIM 的 SROCC 都没有高于 RMSE ，或者残差显著小于 RMSE 。在未来的成像研究中选择 IQM 时，应考虑这些结果。
