Brief Article
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World J Gastroenterol. Jul 7, 2011; 17(25): 3012-3019
Published online Jul 7, 2011. doi: 10.3748/wjg.v17.i25.3012
T1-weighted dual-echo MRI for fat quantification in pediatric nonalcoholic fatty liver disease
Lucia Pacifico, Michele Di Martino, Carlo Catalano, Valeria Panebianco, Mario Bezzi, Caterina Anania, Claudio Chiesa
Lucia Pacifico, Caterina Anania, Department of Pediatrics, Sapienza University of Rome, Viale Regina Elena, 324, 00161-Rome, Italy
Michele Di Martino, Carlo Catalano, Valeria Panebianco, Mario Bezzi, Department of Radiological Sciences, Sapienza University of Rome, Viale Regina Elena, 324, 00161-Rome, Italy
Claudio Chiesa, Institute of Translational Pharmacology, National Research Council, Via del Fosso del Cavaliere, 100, 00133-Rome, Italy
Author contributions: Pacifico L, Anania C and Chiesa C designed the study; Pacifico L, Di Martino M and Anania C collected the data; Di Martino M, Catalano C, Panebianco V and Bezzi M performed the measurements and analyses; Catalano C, Panebianco V and Bezzi M drafted the manuscript; Chiesa C wrote the manuscript; all the authors participated in the critical review and in the final approval of the manuscript.
Supported by A grant from Sapienza University of Rome (Progetti di Ricerca Universitaria 2008-2009)
Correspondence to: Claudio Chiesa, MD, Institute of Translational Pharmacology, National Research Council, Via del Fosso del Cavaliere, 100, 00133-Rome, Italy. claudio.chiesa@ift.cnr.it
Telephone: +39-6-49979215   Fax: +39-6-49979216
Received: December 13, 2010
Revised: March 1, 2011
Accepted: March 8, 2011
Published online: July 7, 2011
Abstract

AIM: To determine in obese children with nonalcoholic fatty liver disease (NAFLD) the accuracy of magnetic resonance imaging (MRI) in assessing liver fat concentration.

METHODS: A case-control study was performed. Cases were 25 obese children with biopsy-proven NAFLD. Controls were 25 obese children matched for age and gender, without NAFLD at ultrasonography and with normal levels of aminotransferases and insulin. Hepatic fat fraction (HFF) by MRI was obtained using a modification of the Dixon method.

RESULTS: HFF ranged from 2% to 44% [mean, 19.0% (95% CI, 15.1-27.4)] in children with NAFLD, while in the controls this value ranged from 0.08% to 4.69% [2.0% (1.3-2.5), P < 0.0001]. HFF was highly correlated with histological steatosis (r = 0.883, P < 0.0001) in the NAFLD children. According to the histological grade of steatosis, the mean HFF was 8.7% (95% CI, 6.0-11.6) for mild, 21.6% (15.3-27.0) for moderate, and 39.7% (34.4-45.0) for severe fatty liver infiltration. With a cutoff of 4.85%, HFF had a sensitivity of 95.8% for the diagnosis of histological steatosis ≥ 5%. All control children had HFF lower than 4.85%; thus, the specificity was 100%. After 12 mo, children with weight loss displayed a significant decrease in HFF.

CONCLUSION: MRI is an accurate methodology for liver fat quantification in pediatric NAFLD.

Keywords: Nonalcoholic fatty liver disease, Children, Obesity, Fast-magnetic resonance imaging, Liver fat quantification