Magnetic resonance imaging and spectroscopy for monitoring liver steatosis

Abstract

Purpose:To compare noninvasive MRI and magnetic resonance spectroscopy (MRS) methods with liver biopsy to quantify liver fat content. Materials and Methods:Quantification of liver fat was compared by liver biopsy, proton MRS, and MRI using inphase/out-of-phase (IP/OP) and plus/minus fat saturation (ϮFS) techniques. The reproducibility of each MR measure was also determined. An additional group of overweight patients with steatosis underwent hepatic MRI and MRS before and after a six-month weight-loss program. Results:A close correlation was demonstrated between histological assessment of steatosis and measurement of intrahepatocellular lipid (IHCL) by MRS (r s ϭ 0.928, P Ͻ 0.0001) and MRI (IP/OP r s ϭ 0.942, P Ͻ 0.0001; FS r s ϭ 0.935, P Ͻ 0.0001). Following weight reduction, four of five patients with Ͼ5% weight loss had a decrease in IHCL of Ն50%. Conclusion:These findings suggest that standard MRI protocols provide a rapid, safe, and quantitative assessment of hepatic steatosis. This is important because MRS is not available on all clinical MRI systems. This will enable noninvasive monitoring of the effects of interventions such as weight loss or pharmacotherapy in patients with fatty liver diseases.

The Diagnosis and Management of Non-alcoholic Fatty Liver Disease: Practice Guideline by the American Association for the Study of Liver Diseases, American College of Gastroenterology, and the American Gastroenterological Association

“…Th e results from these studies using a variety of interventions, either by diet alone ( 81,83,84,89,92,93 ) or in combination with diff erent exercise prescriptions ( 82,85 -88,92,94 ), have consistently reported a signifi cant reduction in liver fat by an average of ~ 40 % (ranging from 20 to 81 % ). Th e degree of hepatic fat reduction was proportional to the intensity of the lifestyle intervention and generally required a body weight loss between ~ 5 and 10 % ( 82,88,92 ).…”

The diagnosis and management of non-alcoholic fatty liver disease: Practice Guideline by the American Association for the Study of Liver Diseases, American College of Gastroenterology, and the American Gastroenterological Association

“…The results from these studies using a variety of interventions, either by diet alone 81,83,84,89,92,93 or in combination with different exercise prescriptions, 82,[85][86][87][88]92,94 have consistently reported a significant reduction in liver fat by an average of $40% (ranging from 20% to 81%). The degree of hepatic fat reduction was proportional to the intensity of the lifestyle intervention and generally required a body weight loss between $5 to 10%.…”

Metabolic Steatosis & Fibrosis: Review of the Non-Invasive Tools for Diagnosis and Screening

“…Generally, the sensitivity and specificity of MRI for the detection of moderate and severe steatosis are greater than 80 and 95%, respectively; in addition, MRI has agreater than 85% sensitivity and a nearly 100% specificity for mild steatosis (intrahepatic fat 5±10%) (Mazhar et al 2009). It was confirmed by many studies which have reported very good correlations between quantitative estimations of hepatic steatosis on MRI compared with liver biopsy (Cowin et al 2008). Nevertheless this technique is very expensive, not always available in hospital and does not quantify fibrosis.…”