Published online Oct 21, 2016. doi: 10.3748/wjg.v22.i39.8812
Peer-review started: May 5, 2016
First decision: May 27, 2016
Revised: June 30, 2016
Accepted: July 31, 2016
Article in press: July 31, 2016
Published online: October 21, 2016
To establish a threshold value for liver fat content between healthy children and those with non-alcoholic fatty liver disease (NAFLD) by using magnetic resonance imaging (MRI), with liver biopsy serving as a reference standard.
The study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis. The assessment of liver fat fraction was performed using MRI, with a high field magnet and 2D gradient-echo and multiple-echo T1-weighted sequence with low flip angle and single-voxel point-resolved ¹H MR-Spectroscopy (¹H-MRS), corrected for T1 and T2* decays. Receiver operating characteristic curve analysis was used to determine the best cut-off value. Lin coefficient test was used to evaluate the correlation between histology, MRS and MRI-PDFF. A Mann-Whitney U-test and multivariate analysis were performed to analyze the continuous variables.
According to MRS, the threshold value between healthy children and those with NAFLD is 6%; using MRI-PDFF, a cut-off value of 3.5% is suggested. The Lin analysis revealed a good fit between the histology and MRS as well as MRI-PDFF.
MRS is an accurate and precise method for detecting NAFLD in children.
Core tip: Differentiating normal from pathologic liver fat storage in children could depend on technical measurements. Using MR-spectroscopy, a cut-off value of 6% demonstrates the best diagnostic performance, otherwise magnetic resonance imaging (MRI)-PDFF cut-off value of 3.5% better discriminates normal weight from obese children. It is confirmed that MRS is an accurate and precise method for detecting non-alcoholic fatty liver disease in children. However, MRI-PDFF- is a feasible alternative to MRS for quantifying liver steatosis.