3D T1 relaxometry pre and post gadoxetic acid injection for the assessment of liver cirrhosis and liver function.

PURPOSE: To assess the diagnostic value of a 3D dual-flip-angle (DFA) T1 mapping technique with whole liver coverage before and after gadoxetic acid injection for assessment of cirrhosis and liver function, compared to blood tests (APRI: aspartate aminotransferase-to-platelet ratio index). MATERIALS AND METHODS: A total of 133 patients who underwent gadoxetic acid-enhanced liver MRI including a 3D FLASH DFA-T1 mapping sequence before and 20min post-contrast (hepatobiliary phase, HBP) were included in this retrospective IRB approved study. T1 values (msec) were measured on pre-contrast and during HBP in liver parenchyma, ΔT1 (%) was calculated as [(T1 pre-T1 post)/T1 pre]×100. T1 and ΔT1 values were compared between cirrhotic and non-cirrhotic patients and between patients stratified using Child-Pugh and Model for End-Stage Liver Disease (MELD) scores using Mann-Whitney U test. Diagnostic performance of T1 mapping parameters vs. APRI for diagnosing cirrhosis and for assessing degree of liver dysfunction was evaluated using ROC analysis. RESULTS: Fifty non-cirrhotic and 83 cirrhotic patients [Child-Pugh A (n=41), B (n=31) and C (n=11)] were included. There was no significant difference in pre-contrast T1 values between cirrhotic and non-cirrhotic patients. T1-HBP and ΔT1 values were significantly different in patients with cirrhosis (p<0.0001) and higher MELD scores (>17) (p=0.003). ΔT1 showed significant strong correlations with Child-Pugh and MELD scores (r=-0.7, p<0.0001; r=-0.56, p<0.001 respectively). Similar AUCs (p=0.9) for detection of liver cirrhosis were observed for T1 HBP (0.83), ΔT1 (0.86) and APRI (0.85); however APRI showed limited sensitivity (≤55%) in comparison with ΔT1 (74.7%) and T1 HBP (80.7%). CONCLUSION: 3D DFA-T1 mapping sequence used before and after gadoxetic acid injection is useful for the diagnosis of cirrhosis and for the assessment of liver function.