Liver enhancement during hepatobiliary phase after Gd-BOPTA administration: correlation with liver and renal function

Objectives To assess the influence of liver and renal function on liver relative enhancement during hepatobiliary phase MRI after Gd-BOPTA administration. Methods In this IRB-approved retrospective cohort study, we included 326 patients who underwent Gd-BOPTA-enhanced 1.5T liver MRI, including hepatobiliary phase (HBP) acquired 90-150 min after injection, in two centres between Jan 2016 and Dec 2019. Liver signal intensity was measured on native and HBP phases and normalized to paraspinal muscles. Liver normalized relative enhancement (NRE) in HBP was calculated and compared with eGFR, total serum bilirubin and HBP acquisition delay by means of Spearmanrcorrelation test and Mann-WhitneyUtest. Results 221/326 patients received 0.05 mmol/Kg Gd-BOPTA (group A), whereas 105/326 received 0.1 mmol/Kg (group B). Liver NRE in HBP was significantly higher in group B than in group A (0.55vs.0.33,p < 0.0001). In both groups, liver NRE in HBP had a negative correlation with total serum bilirubin level (r = - 0.32,p < 0.0001, group A;r = - 0.36,p = 0.0002, group B). Patients with total bilirubin > 1.2 mg/dl showed significantly lower NRE in HBP compared with those with total bilirubin <= 1.2 mg/dl (p < 0.0001, group A;p = 0.04, group B). Patients with impaired liver function in group B showed a NRE during HBP comparable with those with normal liver function in group A. No statistically significant correlation between liver NRE and eGFR or acquisition delay was observed. Conclusions The degree of liver enhancement during HBP is not correlated with eGFR or acquisition delay, but it is significantly reduced in patients with impaired liver function. 0.1 mmol/kg Gd-BOPTA dose might be useful in patients with total serum bilirubin > 1.2 mg/dl.