Quantitative evaluation of functional liver reserve using the liver-to-spleen ΔR 1 ratio based on gadoxetic acid-enhanced MRI: corrected for the effect of gadoxetic acid dose

Abstract

Background

The liver T₁ reduction rate can be used to assess liver function. However, higher doses of gadoxetic acid may shorten the liver T₁ value in the hepatobiliary phase and increase the T₁ reduction rate in patients with severe liver dysfunction, potentially overestimating liver function.

Purpose

To verify the relationship between the gadoxetic acid dose and the liver T₁ reduction rate and ΔR₁ of the liver and spleen, and to clarify whether the ΔR₁ of hepatocytes, corrected for the effect of gadoxetic acid dose, could be used as an index of functional liver reserve.

Material and Methods

We enrolled 13 patients with normal liver function (NLF); and 18, 8, and 3 patients with Child-Pugh classes A (CPA), B (CPB), and C (CPC) who underwent gadoxetic acid-enhanced magnetic resonance imaging. Phase-sensitive inversion recovery sequence was performed before and at 15 min after injection and T₁ maps were calculated. Liver and spleen ΔR₁, liver T₁ reduction rate, and the liver-to-spleen ΔR₁ ratio were calculated.

Results

Only the liver-to-spleen ΔR₁ ratio showed no correlation with gadoxetic acid dose in any group. The T₁ reduction rate was not significantly different between the CPA and CPB + CPC groups. The liver-to-spleen ΔR₁ ratio significantly differed between all groups.

Conclusion

The liver and spleen ΔR₁ was dependent on the dose of gadoxetic acid in severe liver dysfunction. The liver-to-spleen ΔR₁ ratio improves the delineation of the CPA and CPB + CPC groups.