Quantitative analysis of liver function using superparamagnetic iron oxide- and Gd-EOB-DTPA-enhanced MRI: Comparison with Technetium-99m galactosyl serum albumin scintigraphy

摘要

Purpose: To examine whether or not the parameters regarding the signal intensity of the liver parenchyma on superparamagnetic iron oxide (SPIO)- and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)- enhanced MRI are correlated with the parameters of Technetium-99m galactosyl serum albumin ( 99mTc-GSA) scintigraphy. Materials and methods: This retrospective study consisted of 55 and 33 patients who underwent SPIO- and Gd-EOB-DTPA-enhanced MRI in addition to 99mTc-GSA scintigraphy, respectively. For each patient, we calculated Pre R2* and Pre R2, which are equivalent to R2* (=1/T2*) and R2 (=1/T2) values of the liver parenchyma; ΔR2* and ΔR2, which represent differences in R2* and R2 values of the liver parenchyma before and after administration of SPIO; and the increase rates of both the liver-to-spleen signal intensity ratio (LSR) and the liver-to-major psoas muscle signal intensity ratio (LMR) on the hepatobiliary phase compared with the precontrast image. For 99mTc-GSA scintigraphy, the receptor index LHL15 and the blood clearance index HH15 were recorded. Results: Regression analysis showed a moderate correlation between Pre R2* and LHL15 (P 0.05). Mild to moderate correlations were also obtained between any combination of ΔR2* and ΔR2 on the one hand, and LHL15 and HH15 on the other (P 0.05). There were moderate correlations between any combination of increase rates of LSR and LMR on the one hand, and LHL15 and HH15 on the other (P 0.05-0.001). Conclusion: Pre R2*, ΔR2*, ΔR2 and the increase rates of LSR and LMR could be used as quantitative indicators of liver function.