Value of gadoxetate biliary transit time in determining hepatocyte function.

OBJECTIVE: To determine if transit time for excretion of gadoxetate into major bile ducts and duodenum correlates with clinical models of hepatocellular function.

METHODS: This retrospective research was approved by the Institutional Review Board with waiver of informed consent. Search of the radiology database from January 1, 2013 to March 4, 2014 revealed 84 patients with chronic liver disease (65 males, mean age 47 years). Eighteen control subjects with no known liver disease or risk factors were also enrolled for analysis (9 males, mean age 43 years). MRI was performed with hepatobiliary phases at 10, 15, 20, and 25 min after injection of 0.025 mmol/kg of gadoxetate (Primovist, Bayer HealthCare, Shanghai, China). The time of excreted contrast appearing in the biliary tree and in the duodenum was recorded. Linear trend analysis was performed to determine the relationship between excretion time and hepatic function.

RESULTS: The patient cohort was stratified by Child-Pugh classification (A, B, and C with n = 53, 27, and 4, respectively). Arrival of gadoxetate in the gall bladder at 10-min hepatobiliary phase was seen in 87% of control group and 45% of Child-Pugh A group (p = 0.02). There was no difference between these groups for later hepatobiliary phases. The arrival of biliary contrast in the right hepatic duct, common bile duct, and gall bladder were significantly earlier in the Child-Pugh A group compared to the Child-Pugh B/C group at all hepatobiliary phases after 10 min (p < 0.05). Linear trend analysis showed that biliary transit times were significantly delayed with worsening liver function (p = 0.01). There was no difference in entry time of gadoxetate into the duodenum between the normal, Child-Pugh A, and Child-Pugh B/C groups.

CONCLUSIONS: The transit time for gadoxetate to appear in extrahepatic duct is a reasonable indicator of liver function, and may be included in radiology reports. The appearance in the duodenum, however, may depend on factors other than liver function, such as the physiology of the gallbladder and sphincter of Oddi.