title: Imaging patterns and focal lesions in fatty liver: a pictorial review.
abstract: Non-alcoholic fatty liver disease is the most common cause of chronic liver disease and affects nearly one-third of US population. With the increasing trend of obesity in the population, associated fatty change in the liver will be a common feature observed in imaging studies. Fatty liver causes changes in liver parenchyma appearance on imaging modalities including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) and may affect the imaging characteristics of focal liver lesions (FLLs). The imaging characteristics of FLLs were classically described in a non-fatty liver. In addition, focal fatty change and focal fat sparing may also simulate FLLs. Knowledge of characteristic patterns of fatty change in the liver (diffuse, geographical, focal, subcapsular, and perivascular) and their impact on the detection and characterization of FLL is therefore important. In general, fatty change may improve detection of FLLs on MRI using fat suppression sequences, but may reduce sensitivity on a single-phase (portal venous) CT and conventional ultrasound. In patients with fatty liver, MRI is generally superior to ultrasound and CT for detection and characterization of FLL. In this pictorial essay, we describe the imaging patterns of fatty change in the liver and its effect on detection and characterization of FLLs on ultrasound, CT, MRI, and PET.
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. venkatesh.sudhakar@mayo.edu.
authors.forename: Sudhakar K
authors.initials: SK
authors.lastname: Venkatesh
authors.affiliation: Department of Oncologic Imaging, National Cancer Centre, Singapore, Singapore.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Hennedige
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Johnson
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Hough
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Joel G
authors.initials: JG
authors.lastname: Fletcher
mesh_terms: D003937:Diagnosis, Differential; D003952:Diagnostic Imaging / Q000379:methods*; D005234:Fatty Liver / Q000000981:diagnostic imaging*; D006801:Humans
keywords: CT; Fatty liver; Focal liver lesions; Hepatic steatosis; MRI; PET; Ultrasound