Noninvasive Quantitative Assessment of Hepatic Steatosis by Proton Magnetic Resonance Spectroscopy Among Adult Patients Receiving Home Parenteral Nutrition.

BACKGROUND: Intestinal failure-associated liver disease is a frequent complication in patients with chronic intestinal failure (CIF), with steatosis as a dominant feature in adults. Proton magnetic resonance spectroscopy (1H-MRS) is a noninvasive method to quantify liver fat content (LFC). In this study, LFC was assessed with 1H-MRS, taking into account the possible accumulation of paramagnetic components of home parenteral nutrition (HPN) that may disturb these measurements.

METHODS: LFC was measured in 15 adult CIF patients who had been receiving HPN for >6 months. 1H-MR spectra were obtained with a 3 Tesla magnetic resonance (MR) system, with a method correcting for the presence of paramagnetic ions. Patients with low (<5%) versus high (≥5%, steatosis) LFC were compared with nonparametric statistical tests.

RESULTS: 1H-MRS analysis revealed steatosis in 5 patients (median, 10.3%), while 10 patients had normal LFC (median, 0.9%). In all patients, the 1H-MRS results indicated the presence of various amounts of paramagnetic constituents in the liver. Patients with steatosis had higher alanine aminotransferase values than patients without steatosis (median, 60 vs 28 U/L). Unexpectedly, in the steatosis group, the frequency of HPN use was lower, with significant lower total HPN and carbohydrate calories. In 1 patient, MR spectra were of inferior quality, with broadened resonances after infusion with a ferric compound.

CONCLUSION: 1H-MRS enables reliable noninvasive assessment of LFC in patients receiving long-term HPN, if correcting for possible accumulation of paramagnetic components in the liver. However, LFC determination by 1H-MRS is not recommended after a recent ferric compound infusion.