Comparing the Value of the Circular Region-of-interest- and Whole-liver Histogram-based Analysis on Gd-EOB-DTPA-enhanced T1 Map for Predicting Postoperative Liver Failure

The objective of this study is to compare the value of the circular region-of-interest (ROI) and whole-liver histogram-based analysis on gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced T1 map for predicting postoperative liver failure. Forty patients who underwent partial hepatectomy for focal liver lesions were retrospectively analyzed. All subjects underwent 1.5T Gd-EOB-DTPA-enhanced MRI including pre-contrast and hepatobiliary-phase T1 mapping. Patients were divided into two groups with (16 patients) and without (24 patients) postoperative liver failure according to the criteria established by the International Study Group for Liver Surgery (ISGLS). T1 values before enhancement (T1pre) and in the hepatobiliary phase (T1HBP) were measured by outlining a circular ROI on the axial T1 maps. The reduction rate of T1 relaxation time (rrT1) = (T1 pre - T1HBP) / T1 pre. The whole-liver histogram analysis was performed using the prototype MR Multiparametric Analysis software (Siemens Healthcare, Erlangen, Germany). Differences of the circular ROI-based mean values and the histogram parameters between the two groups were compared. The receiver operating characteristic curve (ROC) was plotted. The circular ROI-based mean values and the histogram parameters for predicting PHLF was assessed by the area under the curve (AUC).