Liver fat quantification of multiple lipid peaks using JMRUI

Hi, MRS experts,

I’ve been working on single voxel liver MRS data using jmrui. How do I measure liver fat-fraction from multiple peaks (i.e. 0.9 ppm, 1.3 ppm and 2.1 ppm)? Do I divided the sum signal of total fat peaks by the sum signal of water plus all 3 lipid peaks?

e.g. FF = [S(fat_0.9)+S(fat_1.3)+S(fat_2.1)] / [S(water) + S(fat_0.9) +S(fat_1.3) +S(fat_2.1)].