Department of Radiology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, PR China.
Department of Radiology, Yancheng City No.1 People's Hospital, Yancheng, Jiangsu, PR China.
J Magn Reson Imaging. 2018 Apr;47(4):1003-1012. doi: 10.1002/jmri.25820. Epub 2017 Jul 25.
To prospectively evaluate the short-term reproducibility of intravoxel incoherent motion (IVIM) parameters and apparent diffusion coefficient (ADC) in lung cancer patients.
In all, 50 patients (50 lesions) underwent free-breathing diffusion-weighted imaging (DWI) (b = 0, 300, 800 s/mm ) and IVIM (10 b-values, 0-1000 s/mm ) scans twice (0.5-1-hour interval) at 3T. Regions of interests (ROIs) were drawn on ADC maps and IVIM images to derive the mean ADC value and IVIM parameters D, D*, and f. Intra- and interobserver, test-retest reproducibility were assessed with intraclass correlation coefficients (ICCs), within coefficient-of-variations (WCVs), and Bland-Altman analysis. The effects of type, size, and location of lung lesions were compared with WCVs.
D and ADC showed good intraobserver reproducibility and interobserver agreement, while D* and f showed relatively larger variability (WCV 20.89-34.97%). The test-retest reproducibility of D and ADC were good (ICC 0.763-0.837; WCV 11.12-12.55%), while those of D* and f were relatively poor (ICC 0.604-0.842; WCV 36.54-72.62%). D and ADC had decreased reproducibility for lesions <2 cm (WCV 14.20%, 16.34%, respectively) and for lesions in the lower lung zones (WCV 16.52%, 14.78%, respectively). f had decreased reproducibility in central lung cancers (WCV 50.11%) and lesions >2 cm (WCV 42.64%). D* had even worse reproducibility in peripheral lung cancers (WCV 84.11%) and lesions in the lower lung zones (WCV 80.84%).
If the change in ADC, D, D*, and f values is less than ∼31%, 34%, 170%, and 130%, respectively, it may be caused by measurement error. The type, size, and location of lung lesions have an effect on measurement errors.
1 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2018;47:1003-1012.
前瞻性评估肺癌患者体素内不相干运动（IVIM）参数和表观扩散系数（ADC）的短期可重复性。
共 50 例（50 个病灶）患者在 3T 扫描仪上进行两次自由呼吸弥散加权成像（DWI）（b=0、300、800 s/mm ）和 IVIM（10 个 b 值，0-1000 s/mm ）扫描（0.5-1 小时间隔）。在 ADC 图和 IVIM 图像上绘制感兴趣区（ROI），以得出平均 ADC 值和 IVIM 参数 D、D*和 f。采用组内相关系数（ICC）、组内变异系数（WCV）和 Bland-Altman 分析评估观察者内和观察者间、测试-再测试的可重复性。比较了肺癌病变的类型、大小和位置与 WCV 的关系。
D 和 ADC 显示出良好的观察者内可重复性和观察者间一致性，而 D和 f 显示出相对较大的变异性（WCV 20.89-34.97%）。D 和 ADC 的测试-再测试可重复性良好（ICC 0.763-0.837；WCV 11.12-12.55%），而 D和 f 的可重复性相对较差（ICC 0.604-0.842；WCV 36.54-72.62%）。D 和 ADC 对<2cm 的病变（WCV 分别为 14.20%、16.34%）和下肺区的病变（WCV 分别为 14.78%、16.52%）的可重复性降低。f 在中央肺癌（WCV 50.11%）和>2cm 的病变（WCV 42.64%）中的可重复性降低。D*在周围型肺癌（WCV 84.11%）和下肺区病变（WCV 80.84%）中的可重复性更差。
如果 ADC、D、D*和 f 值的变化分别小于约 31%、34%、170%和 130%，则可能是由测量误差引起的。肺癌病变的类型、大小和位置对测量误差有影响。
1 技术功效分期：1 J. Magn. Reson. Imaging 2018;47:1003-1012.
