Abstract
To evaluate the effect of intravenous gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) on estimation of liver stiffness using magnetic resonance elastography (MRE) for detection of liver fibrosis.
Liver MRI with MRE was performed in 210 subjects on a single 1.5 Tesla clinical MRI scanner. Liver MRE was performed before intravenous Gd-DTPA injection (NC-MRE) and 5 minutes post injection (PC-MRE) using a modified phase-contrast gradient-echo sequence (TR/TE=100/27ms, FOV=30-46cm, 4x10mm slices, gap 5mm) which automatically generated stiffness maps. Two readers' blinded to clinical details independently performed liver stiffness measurements (LSM) by drawing 2 or more regions of interest (ROI) on the stiffness maps on each of the four slices of NC-MRE and PC-MRE obtained for each patient. The mean LSM in kilopascals (kPa) for NC-MRE and PC-MRE was calculated. The correlation between NC-MRE and PC-MRE LSM was evaluated with a paired t test and Pearson's correlation analysis, and the inter-observer correlation was evaluated using intra class coefficient (ICC) analysis. A receiver operating curve analysis (ROC) was performed to compare accuracies for detection and staging of liver fibrosis in a subgroup of 72 subjects with histological confirmation of liver fibrosis.
There was an excellent correlation between NC-MRE and PC-MRE LSM (R-2=0.98, p < 0.001) with no significant differences. The interobserver agreement was also excellent (ICC, 0.94-0.99). There were no significant differences in the cut-off LSM value/accuracy/sensitivity/specificity for detection of significant liver fibrosis with NC-MRE and PC-MRE (2.98kPa/98.5%/100%/88%, p < 0.001 and 3.1kPa/98.2%/98%/88%, p < 0.001 respectively).
Intravenous Gd-DTPA had no significant influence on LSM with MRE and does not significantly affect the diagnostic performance of MRE for fibrosis detection.