Jianqin Jiang1,2, Jianbin Yin1, Lei Cui1, Xiaowen Gu1,3, Rongfang Cai1, Shenchu Gong1, Yiming Xu4, Hang Ma5, Jian Mao6. 1. Department of Radiology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, PR China. 2. Department of Radiology, Yancheng City No.1 People's Hospital, Yancheng, Jiangsu, PR China. 3. Department of Radiology, Suzhou Municipal Hospital, Suzhou, Jiangsu, PR China. 4. Department of Thoracic Surgery, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, PR China. 5. Department of Respiratory, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, PR China. 6. Customer Service, Healthcare, Siemens China.
Abstract
PURPOSE: To prospectively evaluate the short-term reproducibility of intravoxel incoherent motion (IVIM) parameters and apparent diffusion coefficient (ADC) in lung cancer patients. MATERIALS AND METHODS: In all, 50 patients (50 lesions) underwent free-breathing diffusion-weighted imaging (DWI) (b = 0, 300, 800 s/mm2 ) and IVIM (10 b-values, 0-1000 s/mm2 ) 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. RESULTS: 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%). CONCLUSION: 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. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2018;47:1003-1012.
PURPOSE: To prospectively evaluate the short-term reproducibility of intravoxel incoherent motion (IVIM) parameters and apparent diffusion coefficient (ADC) in lung cancerpatients. MATERIALS AND METHODS: In all, 50 patients (50 lesions) underwent free-breathing diffusion-weighted imaging (DWI) (b = 0, 300, 800 s/mm2 ) and IVIM (10 b-values, 0-1000 s/mm2 ) 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. RESULTS: 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%). CONCLUSION: 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. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2018;47:1003-1012.