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.