Assessing Liver Function in Liver Tumors Patients: The Performance of T1 Mapping and Residual Liver Volume on Gd-EOBDTPA-Enhanced MRI.

Purpose:To assess the performance of T1 mapping and residual liver volume (RLV) on Gd-EOBDTPA-enhanced MRI in pretreatment estimation of liver function in patients with liver tumors. Indocyanine green retention rate at 15 min (ICG R-15) was used as a reference standard. Methods:Ethical approval from the institutional review board and informed consent were obtained for this prospective study. We enrolled 155 patients with liver tumors who underwent pretreatment Gd-EOB-DTPA-enhanced MRI. T1 relaxation time before (T1-pre), 20 min after (T1-post) Gd-EOB-DTPA injection and RLV were measured. The absolute reduction (Delta T1) and reduction rate (Delta T1%) of T1 relaxation time, volume-assisted Delta T1 (Delta T1*RLV) and volume-assisted Delta T1% (Delta T1%*RLV) were calculated accordingly. The correlation of MR parameters with ICG R-15 was determined using Spearman's rank correlation analysis. Patients were classified into the normal liver function (NLF) group if their ICG R-15 levels were <10% or otherwise into the abnormal liver function (ALF) group. Receiver operating characteristic (ROC) analysis was conducted to evaluate the performances of the MR parameters in predicting ALF. Results:T1-post (r= 0.472,P< 0.001), Delta T1 (r= -0.355,P= 0.011), Delta T1% (r= -0.482,P< 0.001), RLV (r= -0.336,P< 0.001), volume-assisted Delta T1 (r= -0.458,P< 0.001) and volume-assisted Delta T1% (r= -0.522,P< 0.001) showed weak to moderate correlation with ICG R-15. The area under the ROC curves (AUROC) of volume-assisted Delta T1 in predicting ALF was 0.777, which was significantly higher than the other parameters (P< 0.05 for all). Conclusions:Combined T1 mapping and RLV on Gd-EOB-DTPA-enhanced MRI can help assess liver function with good diagnostic accuracy in patients with liver tumors before treatment.