Focal fatty sparing areas of the pediatric steatotic liver: pseudolesions on hepatobiliary phase magnetic resonance images

OpenAlex · İngilizce

on-alcoholic fatty liver disease has become common among children and includes a broad range of clinicopathologic features ranging from simple steatosis (fat without inflammation and/or fibrosis) and steatohepatitis/non-alcoholic steatohepatitis to cirrhosis. 1 Fatty liver in children can have various imaging manifestations, including diffuse and homogeneous, geographic, focal, and multifocal fat accumulation.2 Focal areas of steatosis and fatty sparing in the liver can be detected as mass-like pseudolesions on ultrasonography or computed tomography (CT); in addition, these pseudolesions may show increased fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET)/CT.3 Distinguishing these pseudolesions from metastases, particularly in pediatric patients with cancer, is crucial for preventing misdiagnosis.Liver magnetic resonance imaging (MRI) could be utilized as a problem-solving tool to assess focal liver lesions detected in a steatotic liver in both children and adults.Recently, the use of hepatobiliary contrast agents in children has become more common, and although these pseudolesions can be easily recognized with dual-echo imaging, hepatobiliary phase imaging may cause confusion because of metabolic alterations of liver parenchyma. PURPOSEFocal fatty sparing in liver can be detected as hyperintense pseudolesions on hepatobiliary phase magnetic resonance imaging (MRI).Distinguishing these pseudolesions from liver lesions may make diagnosis challenging.The aim of this study was to evaluate the imaging features of fatty sparing areas on liver MRI in pediatric patients who have been administered gadoxetate disodium. METHODSA total of 63 patients between January 2018 and June 2023 underwent gadoxetate disodium-enhanced liver MRI, and 9 (14%) patients with a focal fatty sparing were included in the study.The fat spared areas were evaluated qualitatively and quantitatively including signal intensity measurements and fat fraction calculations. RESULTSThe liver MRI examinations of 9 patients (5 boys, 4 girls; aged 8-18 years, median age: 14.4) using gadoxetate disodium were evaluated.Based on in-phase and opposed-phase sequences, 13 areas of focal fatty sparing were identified.The mean fat fraction of the liver and fat spared areas were 26.2% (range, 15-47) and 9% (range, 2-17), respectively.All fat spared areas were hyperintense in the hepatobiliary phase images.The mean relative enhancement ratios of the liver and fat spared areas were 0.78 (range, 0.35-1.6)and 1.11 (range, 0.45-1.9),respectively. CONCLUSIONFocal fatty sparing in liver in children was observed as hyperintense on hepatobiliary phase MRI, and it should not be identified as a focal liver lesion.