Initial study of quantitative analysis of fatty liver by ¹H-MR spectroscopy imaging

Objective: To investigate the feasibility of ¹H-MR spectroscopy (¹H-MRS) imaging to quantitatively detect fatty liver. Methods: Twenty patients with fatty liver and 11 healthy volunteers underwent plain CT scan, conventional MR imaging and ¹H-MRS analysis. The blood lipid and liver function were tested on the same day as the MR examination. ¹H-MRS sequence measured the peaks of H₂O and lipid, and the areas under the peaks. The relative contents of the lipid compound were calculated, and compared with the results of CT scan and liver function tests. Results: The CT values of the normal group and the fatty liver group were (59 ± 9) HU and (24 ± 11) HU respectively. On ¹H-MRS a protruding high H₂O peak and a flat low lipid peak were observed in the normal group, while the protruding high H₂O peak and a high lipid peak appeared in the fatty liver group. The values of lipid peak in the normal group and the fatty liver group were (0.05 ± 0.01) x l0⁵, (0.70 ± 0.24) x l0⁵ respectively (t=4.32, P<0.05), the values of H20 peak were (1.80 ± 0.52) x l0⁵, (1.85 ± 0.47) x l0⁵ respectively (t=1.26, P>0.05), the areas under the lipid peak were (1.36 ± 0.73) x 10⁹, (2.35 ± 1.15) x 10⁹ respectively (t=5.21, P< 0.05), and the areas under the H₂O peak were (4.33 ± 1.28) x 10¹¹, (3.55 ± 0.94) x 10¹¹ respectively (t=2.04, P>0.05). Conclusion: ¹H-MRS imaging is feasible to quantitatively detect liver fat and is a non-invasive method for detecting early fatty liver. (authors)