Multimodal perioperative assessment of liver function and volume in patients undergoing hepatectomy for colorectal liver metastasis : a comparison of the indocyanine green retention test, 99mTc mebrofenin hepatobiliary scintigraphy and gadoxetic acid enhanced MRI

Objectives: To compare the dynamic changes in future liver remnant (FLR) function and volume after hepatec-tomy and to evaluate the associations between three modalities in assessment of liver function.Methods: Liver function and volume were quantified pre-operatively, at post-operative day (POD) 7 and POD 28 in 10 patients with colorectal liver metastases under-going hemihepatectomy using the indocyanine green retention (ICG) test, hepatobiliary scintigraphy (HBS) and gadoxetic acid-enhanced MRI. The 99mTc mebro-fenin uptake rate in the FLR was applied as a reference of liver function. MRI-derived parameters including liver- to-muscle ratio (LMR), liver - to-spleen ratio (LSR) and hepatocellular uptake index (HUI) were used for liver function assessment. Spearman's correlation analysis was used to evaluate the associations.Results: Increase in liver function ranged from 13 to 152% (median 92%) and in volume from 37 to 134% (median 79%). There was no significant discrepancy in increase between FLR function and volume during the first month following hepatectomy. LMR showed a significant corre-lation to ICG test (r = -0.66, p < 0.05) while LSR had an association with standardized FLR function obtained by HBS (r = -0.71, p < 0.05). During the first week after hepatectomy, pre-operative HUI and LMR showed the strongest correlation to the FLR growth in function and volume respectively (p < 0.05).Conclusion: The observed growth in FLR volume is closely related to the functional increase within 1 month after hepatectomy. Gadoxetic acid-enhanced MRI might substitute HBS for regional liver function assessment and provide an imaging tool for liver growth prediction.Advances in knowledge: Liver function growth was parallel with liver volume increase during the perioper-ative period. Liver function assessment with gadoxetic acid-enhanced MRI was comparable with that of HBS indicating that gadoxetic acid-enhanced MRI could substitute HBS for regional liver function evaluation