Abstract

ABSTRACT:
BACKGROUND:
Hepatic steatosis is a broad term; nonalcoholic fatty liver disease (NAFLD) is the most common type. Magnetic resonance imaging (MRI) can provide a quantitative, accessible and accurate evaluation of diffuse liver disease.
OBJECTIVE:
Study the role of MRI Dixon in quantification of hepatic fat in patients with NAFLD in correlation with (computed tomography) CT attenuation, serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST) and body mass index (BMI)
PATIENTS AND METHODS:
This cross sectional analytic prospective study was conducted from November 2016 to December 2017 at radiology department of Al-Imamein Al Kadhimein Medical City, Baghdad/ Iraq. Fifty patients were included in this study (28 females and 22 males), the study included patients with clinical and laboratory suspicion of NAFL and CT evidence of fatty liver (in unenhanced CT the liver parenchyma were less than 40 Hounsfield unit (HU), or if CT attenuation of the liver were 10 HU less than that of spleen). All patients were examined with T1 vibe Dixon sequence with breath hold. Hepatic fat fraction (HFF) was calculated from mean ROIs of water and fat images using following formula: % of HFF=F/F+W, where W and F are the signal contribution from water and fat respectively.
RESULTS:
The cases were divided into 3 groups according to the results of MRI Dixon fat fraction % as following: group A MRI Dixon fat was less than 15% (21 patients), group B between 15 -30% (13 patients) and group C more than 30% (16 patients). There was statistically significant relationship between Dixon fat fraction with CT attenuation in group A and C while no statistically significant relationship was seen in group B. There was no statistically significant relationship between Dixon fat fraction and serum ALT and AST in group A and B while statistically significant relationship between Dixon fat fraction and serum ALT was found in group C. there was statistically significant relationship between Dixon fat fraction and body mass index in all 3 groups.
CONCLUSION:
Dixon MRI was noninvasive, reliable technique in quantification of fat fraction in NAFL, Dixon MRI was more sensitive sequence for early detection of fatty liver diseases infiltration.
KEYWORDS: Dixon Magnetic resonance imaging, liver fat, fatty liver disease