Hepatobiliary MRI: Signal intensity based assessment of liver function correlated to (13)C-Methacetin breath test

Gadoxetic acid (Gd-EOB-DTPA) is a paramagnetic MRI contrast agent with raising popularity and has been used for evaluation of imaging-based liver function in recent years. In order to verify whether liver function as determined by real-time breath analysis using the intravenous administration of (13)C-methacetin can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using signal intensity (SI) values. 110 patients underwent Gd-EOB-DTPA-enhanced 3-T MRI and, for the evaluation of liver function, a (13)C-methacetin breath test ((13)C-MBT). SI values from before (SI(pre)) and 20 min after (SI(post)) contrast media injection were acquired by T1-weighted volume-interpolated breath-hold examination (VIBE) sequences with fat suppression. The relative enhancement (RE) between the plain and contrast-enhanced SI values was calculated and evaluated in a correlation analysis of (13)C-MBT values to SI(post) and RE to obtain a SI-based estimation of (13)C-MBT values. The simple regression model showed a log-linear correlation of (13)C-MBT values with SI(post) and RE (p < 0.001). Stratified by 3 different categories of (13)C-MBT readouts, there was a constant significant decrease in both SI(post) (p ≤ 0.002) and RE (p ≤ 0.033) with increasing liver disease progression as assessed by the (13)C-MBT. Liver function as determined using real-time (13)C-methacetin breath analysis can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using SI-based indices.