Correlation between liver histology and novel magnetic resonance imaging in adult patients with non‐alcoholic fatty liver disease – MRI accurately quantifies hepatic steatosis in NAFLD

Abstract

SUMMARY Background Conventional magnetic resonance imaging (MRI) techniques that measure hepatic steatosis are limited by T1 bias, T2* decay and multi-frequency signal-interference effects of protons in fat. Newer MR techniques such as the proton density-fat fraction (PDFF) that correct for these factors have not been specifically compared to liver biopsy in adult patients with non-alcoholic fatty liver disease (NAFLD). Aim To examine the association between MRI-determined PDFF and histology-determined steatosis grade, and their association with fibrosis. Methods A total of 51 adult patients with biopsy-confirmed NAFLD underwent meta-bolic-biochemical profiling, MRI-determined PDFF measurement of hepatic steatosis and liver biopsy assessment according to NASH-CRN histological scoring system. Results The average MRI-determined PDFF increased significantly with increasing histology-determined steatosis grade: 8.9% at grade-1, 16.3% at grade-2, and 25.0% at grade-3 with P ≤ 0.0001 (correlation: r2 = 0.56, P < 0.0001). Patients with stage-4 fibrosis, when compared with patients with stage 0–3 fibrosis, had significantly lower hepatic steatosis by both MRI-determined PDFF (7.6% vs. 17.8%, P < 0.005) and histology-determined steatosis grade (1.4 vs. 2.2, P < 0.05). NAFLD patients with grade 1 steatosis were more likely to have characteristics of advanced liver disease including higher average AST:ALT (0.87 vs. 0.60, P < 0.02), GGT (140 vs. 67, P < 0.01), and INR (1.06 vs. 0.99, P < 0.01), higher stage of fibrosis and hepatocellular ballooning. Conclusions MRI-determined proton density-fat fraction correlates with histology-determined steatosis grade in adults with NAFLD. Steatosis is non-linearly related to fibrosis progression. In patients with NAFLD, a low amount of hepatic steatosis on imaging does not necessarily indicate mild disease.

Imaging-Based Assessment of Steatosis, Inflammation and Fibrosis in NAFLD

“…The advantage of magnetic resonance imaging-proton-derived fat fraction (MRI-PDFF) over previous methods is that it gives a global assessment of liver fat, whereas techniques, such as MR spectroscopy, measure fat from regions of interest within the liver, which can be associated with sampling variability [26]. Recent cross-sectional studies have shown that PDFF correlates well with histological assessment of steatosis (r 2 = 0.54, p < 0.001 and r 2 = 0.69, p < 0.001, respectively) [25,27] and can accurately distinguish between the presence or absence of hepatic steatosis (AUROC of 0.989) [25]. MRI-PDFF also had good inter-examination accuracy for whole liver assessment (ICC = 0.999; SD < 0.24%, range < 0.45%) [28].…”

Nonalcoholic fatty liver disease with cirrhosis increases familial risk for advanced fibrosis

“…MRI-PDFF has been shown to be a highly precise, accurate, and reproducible noninvasive biomarker for the quantification of liver fat content (41,42). It has been proven to correlate well with magnetic resonance spectroscopy (r 2 = 0.99, P < 0.001) (30,43) and histology-proven steatosis grade from contemporaneous liver biopsies (36,40), and it is superior to ultrasound and CT for quantification of liver fat content (44). Rationale for using MRE-stiffness for hepatic fibrosis quantification.…”

“…MRI-PDFF was used to measure hepatic steatosis, and MRE was used to measure hepatic fibrosis. The details of the MRI protocol have been previously described in references (31,40). The image analysts were blinded to all clinical and biochemical data, including the study group of the participants.…”

Non-alcoholic fatty liver disease

“…[Au: Some information moved to the figure legend.] In numerous single-centre and multi-centre studies, PDFF has shown high accuracy for diagnosing, grading, and longitudinally monitoring steatosis in adults and children, including morbidly obese individuals [142][143][144][145][146][147] .…”