A new magnetic resonance imaging (MRI)-based technique called magnitude-based MRI may help in the detection and evaluation of nonalcoholic fatty liver disease (NAFLD) in children, results from new study indicate.
Currently, according to study author Jeffrey B. Schwimmer, MD, of the University of California, San Diego, diagnosis of NAFLD requires a liver biopsy, which is not always available or performed.
“This leads to both misdiagnosis and missed diagnoses, hampering patient care and progress in clinical research,” he said in a press release. “Thus, a noninvasive method for diagnosing and/or evaluating NAFLD has the potential to impact millions of children.”
This led Dr. Schwimmer and colleagues to conduct a prospective study, recently published in the journal Hepatology.
In the study, researchers enrolled 174 children (mean age, 14 years; age range, 8 to 17 years) to compare standard liver biopsy with the new magnitude-based MRI, which was developed by researchers at the University of California, San Diego Liver Imaging Group.
Specifically, each patient received MRI-estimated proton density fat fraction (PDFF), a biomarker of liver fat content, and the data were compared with those obtained via liver biopsy.
Results indicated that MRI-estimated liver PDFF correlated with steatosis grade (P<.01). This association was stronger in girls vs. boys (P<.01) and weaker in children with stage 2 to 4 fibrosis when compared with those with no fibrosis or stage 1 fibrosis (P<.01).
The researchers used common threshold values to distinguish between no steatosis and mild steatosis, and the diagnostic accuracy ranged from 0.69 to 0.82. A 56% accuracy was reported for predicting the histologic steatosis grade from MRI-estimated liver PDFF.
In addition, there was no single threshold value with sufficient sensitivity or specificity to be considered diagnostic for an individual child, according to the researchers.
Since PDFF is a standardized marker that is reproducible on different scanners and at different imaging centers, the present results can be generalized to the broader population, Dr. Schwimmer said in the release.
“Advanced magnitude MRI can be used to estimate PDFF in children, which correlates well with standard analysis of liver biopsies,” he said. “We are especially excited about the promise of the technology for following children with NAFLD over time. However, further refinements will be needed before this or any other MRI technique can be used to diagnose NAFLD in an individual child.”