Impact of sequential proton density fat fraction for quantification of hepatic steatosis in nonalcoholic fatty liver disease

Abstract

Objective. To determine the utility of sequential MRI-estimated proton density fat fraction (MRI-PDFF) for quantification of the longitudinal changes in liver fat content in individuals with nonalcoholic fatty liver disease (NAFLD). Methods. A total of 18 consecutive individuals (M/F: 10/8, mean age: 47.7 ± 9.8 years) diagnosed with NAFLD, who underwent sequential PDFF calculations for the quantification of hepatic steatosis at two different time points, were included in the study. All patients underwent T1-independent volumetric multi-echo gradient-echo imaging with T2* correction and spectral fat modeling. Results. A close correlation for quantification of hepatic steatosis between the initial MRI-PDFF and liver biopsy was observed (r_s = 0.758, p < 0.001). The median interval between two sequential MRI-PDFF measurements was 184 days. From baseline to the end of the follow-up period, serum GGT level and homeostasis model assessment score were significantly improved (p = 0.015, p = 0.006, respectively), whereas BMI, serum AST, and ALT levels were slightly decreased. MRI-PDFFs were significantly improved (p = 0.004). A good correlation between two sequential MRI-PDFF calculations was observed (r_s = 0.714, p = 0.001). With linear regression analyses, only delta serum ALT levels had a significant effect on delta MRI-PDFF calculations (r² = 38.6%, p = 0.006). At least 5.9% improvement in MRI-PDFF is needed to achieve a normalized abnormal ALT level. The improvement of MRI-PDFF score was associated with the improvement of biochemical parameters in patients who had improvement in delta MRI-PDFF (p < 0.05). Conclusions. MRI-PDFF can be used for the quantification of the longitudinal changes of hepatic steatosis. The changes in serum ALT levels significantly reflected changes in MRI-PDFF in patients with NAFLD.

Key Words::

• follow-up
• hepatic steatosis
• MRI
• nonalcoholic fatty liver disease
• PDFF

Acknowledgments

None of the authors have relevant conflicts of interest to disclose. All authors agree with the manuscripts submission and its content. ISI collected data, conceived and carried out experiments, OK collected data, AHE analyzed data, RI and MK conceived and carried out experiments.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.