Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin 2nd Road, Huangpu District, Shanghai, 200025, China.
Department of Imaging, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, No. 1111 Xianxia Road, Changning District, Shanghai, 200336, China.
Eur Radiol. 2022 Aug;32(8):5480-5490. doi: 10.1007/s00330-022-08628-3. Epub 2022 Feb 22.
To evaluate inter- and intra- scan mode and scanner repeatability and reproducibility of radiomics features within and between single-energy CT (SECT) and dual-energy CT (DECT).
A standardized phantom with sixteen rods of clinical-relevant densities was scanned on seven DECT-capable scanners and three SECT-only scanners. The acquisition parameters were selected to present typical abdomen-pelvic examinations with the same voxel size. Images of SECT at 120 kVp and corresponding 120 kVp-like virtual monochromatic images (VMIs) in DECT which were generated according to scanners were analyzed. Regions of interest were drawn with rigid registrations to avoid variations due to segmentation. Radiomics features were extracted via Pyradiomics platform. Test-retest repeatability was evaluated by Bland-Altman analysis for repeated scans. Intra-scanner reproducibility for different scan modes was tested by intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC). Inter-scanner reproducibility among different scanners for same scan mode was assessed by coefficient of variation (CV) and quartile coefficient of dispersion (QCD).
The test-retest analysis presented that 92.91% and 87.02% of the 94 assessed features were repeatable for SECT 120kVp and DECT 120 kVp-like VMIs, respectively. The intra-scanner analysis for SECT 120kVp vs DECT 120 kVp-like VMIs demonstrated that 10.76% and 10.28% of features were with ICC > 0.90 and CCC > 0.90, respectively. The inter-scanner analysis showed that 17.09% and 27.73% of features for SECT 120kVp were with CV < 10% and QCD < 10%, and 15.16% and 32.78% for DECT 120 kVp-like VMIs, respectively.
The majority of radiomics features were non-reproducible within and between SECT and DECT.
• Although the test-retest analysis showed high repeatability for radiomics features, the overall reproducibility of radiomics features within and between SECT and DECT was low. • Only about one-tenth of radiomics features extracted from SECT images and corresponding DECT images did match each other, even their average photon energy levels were considered alike, indicating that the scan mode potentially altered the radiomics features. • Less than one-fifth of radiomics features were reproducible among multiple SECT and DECT scanners, regardless of their fixed acquisition and reconstruction parameters, suggesting the necessity of scanning protocol adjustment and post-scan harmonization process.
评估单能量 CT（SECT）和双能量 CT（DECT）内和之间的放射组学特征的扫描模式内和扫描间、以及扫描仪重复性和再现性。
在七台具备 DECT 能力的扫描仪和三台仅具备 SECT 的扫描仪上扫描一个具有临床相关密度的十六根棒的标准化体模。选择采集参数以呈现具有相同体素大小的典型腹部-骨盆检查。分析 SECT 的 120kVp 图像和 DECT 中根据扫描仪生成的相应 120kVp 虚拟单能量图像（VMI）。使用刚性配准绘制感兴趣区域，以避免由于分割而导致的变化。通过 Pyradiomics 平台提取放射组学特征。通过 Bland-Altman 分析评估重复扫描的测试-再测试重复性。通过内类相关系数（ICC）和一致性相关系数（CCC）测试不同扫描模式下的扫描仪内再现性。通过变异系数（CV）和四分位系数离散度（QCD）评估相同扫描模式下不同扫描仪之间的扫描仪间再现性。
测试-再测试分析表明，94 个评估特征中 92.91%和 87.02%分别为 SECT 120kVp 和 DECT 120kVp 类似 VMI 的可重复性特征。SECT 120kVp 与 DECT 120kVp 类似 VMI 的扫描仪内分析表明，分别有 10.76%和 10.28%的特征具有 ICC>0.90 和 CCC>0.90。扫描仪间分析显示，SECT 120kVp 的 17.09%和 27.73%的特征的 CV<10%和 QCD<10%，而 DECT 120kVp 类似 VMI 的特征分别为 15.16%和 32.78%。
大多数放射组学特征在 SECT 和 DECT 内和之间不可再现。
• 尽管测试-再测试分析显示放射组学特征具有高重复性，但 SECT 和 DECT 内和之间放射组学特征的整体再现性较低。
• 即使考虑到平均光子能量水平相似，从 SECT 图像和相应的 DECT 图像中提取的放射组学特征中也只有大约十分之一相互匹配，这表明扫描模式可能改变了放射组学特征。
• 无论其固定采集和重建参数如何，在多个 SECT 和 DECT 扫描仪中，只有不到五分之一的放射组学特征具有再现性，这表明需要调整扫描协议并进行扫描后协调。
