Efficacy of a combination of gadolinium?ethoxybenzyl?diethylenetriamine pentaacetic acid enhanced MR T1 mapping and liver volume to standard liver volume ratio for estimation of liver function / 中华放射学杂志

ABSTRACT

ObjectiveTo investigate the feasibility of a combination of gadolinium?ethoxybenzyl?diethylenetriamine pentaacetic acid (Gd?EOB?DTPA) enhanced MR T1 mapping and liver volume to standard liver volume ratio in quantitative assessment of liver function. Methods Eighty patients who underwent Gd?EOB?DTPA enhanced MR T1 mapping were prospectively enrolled, and the Child?Pugh score and the model for end?stage liver (MELD) score were evaluated and grouped. Patients were divided into three groups according Child?pugh score as follows normal liver function (NLF, n=26), liver cirrhosis with Child?Pugh A (LCA,n=30), liver cirrhosis with Child?Pugh B+C (LCB+LCC, n=24), and were also divided into two groups according MELD, MELD≤8 (n=57) and MELD≥9 (n=23). Variable flip angle T1 mapping sequences were performed before and 20 minutes after Gd?EOB?DTPA administration. T1pre, T1 post were measured on T1 maps and &Delta;T1 were calculated. The images of hepatobiliary phase were transferred to the workstation to measure liver volume (LV). Standard liver volume (SLV) were calculated with the heights and weights of patients, and then liver volume to standard liver volume ratio (LV/SLV) was calculated. One?way ANOVA was used to compared the indexes (T1 post, T1 post×LV/SLV, &Delta;T1, &Delta;T1×LV/SLV) in different liver function groups of NLF,LCA,LCB+LCC. The t tests were used to compare the indexes(T1post, T1post×LV/SLV, &Delta;T1, &Delta;T1×LV/SLV) in MELD≤8 and MELD≥9 groups. ROC curve analysis was used to compare the diagnostic performance of T1post, T1post×LV/SLV, &Delta;T1, &Delta;T1×LV/SLV. Results T1post, T1post×LV/SLV, &Delta;T1, &Delta;T1×LV/SLV showed significant difference between different liver function groups (P<0.05). All the indexes can distinguish different groups. Multiplied by LV/SLV,the AUC of &Delta;T1×LV/SLV were 0.902 in the MELD≤8 and MELD≥9,which was slightly higher than that of &Delta;T1 (AUC=0.886). The AUCs of &Delta;T1×LV/SLV were 0.771, 1.000, 0.924 in the NLF and LCA, NLF and LCB+LCC, LCA and LCB+LCC groups, which were slightly higher than that of &Delta;T1 (0.764, 0.992, 0.904). The AUCs of T1post, T1post×LV/SLV were 0.824, 0.789 in the MELD≤8 and MELD≥9, respectively. The AUCs of T1post in the NLF and LCA, NLF and LCB+LCC, LCA and LCB+LCC groups were 0.713,0.987,0.915, respectively, and the AUCs of T1post×LV/SLV were 0.687,0.973,0.871.The AUCs of T1post×LV/SLV had a slightly lower AUC amongthe different liver function groups than T1post. Conclusion Gd?EOB?DTPA enhanced MRI T1 mapping is useful for estimating liver function. T1 relaxation times and reduction rates of T1 relaxation times with a combination of the LV/SLV may more reliably estimate liver function.