Wen Qian, Fei-Yun Wu, Hai-Bin Shi, Jiang-Fen Wu, Guo-Yi Su, Hao Hu, Xiao-Quan Xu
Previous studies indicated that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could serve as a useful biomarker for differentiating malignant from benign orbital lymphoproliferative disorders (OLPDs).
To investigate the influence of different region of interest (ROI) selection methods on the measurements of DCE-MRI parameters, and their diagnostic ability in discriminating malignant from benign OLPDs.
In all, 46 patients with OLPDs (22 benign and 24 malignant).
3.T DCE-MRI using a 2D turbo fast low angle shot sequence postcontrast.
DCE-MRI data were analyzed using three different ROI selection methods, including whole-tumor ROI (ROIWT), single-slice ROI (ROISS) and hot-spot ROI (ROIHS). Quantitative parameters (Ktrans, Kep, Ve) were calculated based on a modified Tofts model.
Analysis of variance test, intraclass correlation coefficient (ICC), Bland–Altman plots, independent t-test, and receiver operating characteristic curve analyses were used for statistical analyses.
The time required for outlining ROIWT was significantly longer than ROISS and ROIHS (P < 0.001). The measurements of DCE-MRI-derived parameters based on ROIHS demonstrated lowest ICC, followed by ROISS and ROIWT. Malignant OLPDs showed significantly higher Kep than benign mimics (P < 0.001), while no significant differences were found on Ktrans (ROIWT, P = 0.535; ROISS, P = 0.557; ROIHS, P = 0.400) and Ve (ROIWT, P = 0.071; ROISS, P = 0.079; ROIHS, P = 0.057). Kep-ROIWT showed the highest area under curve for differentiating malignant from benign OLPDs, followed by Kep-ROISS, and Kep-ROIHS; however, the differences were not significant (ROIWT vs. ROISS, P = 0.407; ROIWT vs. ROIHS, P = 0.363; ROISS vs. ROIHS, P = 0.887).
ROI selection methods could have an influence on the measurements of DCE-MRI parameters. Taking measurement time, reproducibility, and diagnostic ability into account, we suggest single-slice ROI to be used for differentiating malignant from benign OLPDs in clinical practice.
Level of Evidence: 3
Technical Efficacy: Stage 2
J. Magn. Reson. Imaging 2017.