Article Text
Abstract
Introduction Hepatic steatosis is an important co-factor of liver fibrosis progression and is becoming increasingly prevalent. The aim of this study was to evaluate the relationship of liver fibrosis with hepatic lipid composition assessed using proton magnetic resonance spectroscopy (1 H MRS).
Methods Patients (n = 168) were recruited to have 1 H-MRS prior to clinically indicated liver biopsy. A control group of healthy volunteers (n = 49) was also included. MR spectra were analysed for hepatic lipid content (HLC; percentage of fat / water signal), and for the saturation index (SI; percentage of saturated / total lipid content). Fibrosis was staged histologically according to the Ishak staging system and categorised as early (F0-2), bridging (F3-4) and advanced (F5-6). Steatosis was quantified as a percentage of hepatocytes containing lipid droplets.
Results The mean patient age was 51.9±12.19, and patients had a mean BMI of 29.9±7.40. Most patients were men (n = 104, 61.9%), and the most common liver disease aetiologies were NAFLD (n = 79, 47.0%) and viral hepatitis (n = 50, 29.8%). HLC measured using 1 H MRS correlated strongly with the histological fat percentage. (r2=0.73, p < 0.0001). The mean HLC was higher in patients with early (9.6%,p < 0.0001), bridging (11.5%,p
< 0.0001), and advanced fibrosis (6.3%, p = 0.0318) as compared to healthy controls (1.7%; Figure 1 A). The mean SI increased progressively from healthy controls (76.9%) to early (81.9%), bridging (82.6%), and advanced (83.7%) fibrosis (test for trend, p < 0.0001) (Figure 1 B). There was no correlation between HLC, SI, and patient body mass index (BMI).
Conclusion The study demonstrates that in vivo analysis of hepatic lipid composition is feasible using 1 H MRS. The results also suggest that there may be a pathological relationship between saturated fat and fibrosis, as there is a significant trend for higher content of saturated fat in more advanced stages of fibrosis.
Disclosure of Interest C.-M. Tang: None Declared, R. Banerjee Shareholder of: Perspectum Diagnostics, Employee of: Perspectum Diagnostics, Conflict with: Patent applications in the field of non-invasive assessment of liver disease using magnetic resonance imaging techniques, J. Collier: None Declared, J. Booth: None Declared, L. M. Wang: None Declared, K. Fleming: None Declared, S. Neubauer Shareholder of: Perspectum Diagnostics, Conflict with: On the board of directors for Perspectum Diagnostics, and has filed patent applications in the field of non-invasive assessment of liver disease using magnetic resonance imaging techniques, E. Barnes Shareholder of: Perspectum Diagnostics, Conflict with: Patent applications in the field of non-invasive assessment of liver disease using magnetic resonance imaging techniques, J. Cobbold: None Declared, M. Pavlides Shareholder of: Perspectum Diagnostics, Conflict with: Patent applications in the field of non-invasive assessment of liver disease using magnetic resonance imaging techniques