Learning objectives
List the wide spectrum of fat-containing lesions of the liver and identify the imaging features.
Background
The presence of fat in a hepatic lesion is not an unusual finding.
Identifying the fat is a crucial step in the process of diagnosing aetiology.
Although a variety of liver lesions mayshow fat on cross-sectional imaging,
the presence of fat usually indicates that the lesion is of hepatocellular origin.
Fat may be macroscopic or microscopic.
MRI is the modality of choice for detecting a fatty component in a hepatic lesion: fat-saturation sequence detects extracellular fat while chemical shift imaging identifies microscopic or intracellular lipids.
Findings and procedure details
The differential diagnosis of a fat-containing liver mass is usually limited to masses of hepatocellular origin. Fat-containing liver lesions of nonhepatocellular origin are less common and may be identifiedby ancillary imaging or clinical features.
- Fat-Containing Hepatocellular Lesions
Hepatocellular adenomas (HCA)
HCAs are uncommon benign tumors, usually encountered in women with a history of oral contraceptive use,
athletes taking anabolic steroids,
or patients with metabolic diseases.
The main complications of HCA are hemorrhage,
which typically occurs in tumors larger than 5 cm,
and malignant transformation,...
Conclusion
The identification of fat within a liver lesion,
along with other radiological signs and reflection on the clinical and epidemiological context,
can lead to a diagnosis being reached or suggested,
with confirmation if necessary,
by a pathological examination.
Although the presence of fat can be documented with CT or US,
MR imaging is the most specific imaging technique for demonstrating both microscopic and macroscopic fat.
References
1 M.
Tekath,
T.
Klotz,
P.F.
Montoriol,
J.
Joubert-Zakeyh,
J.-M.
Garcier,
D.
Da Ines.
Fat-containing lesions of the liver : A pictorial essay.
Diagnostic and Interventional Imaging (2015) 96,
201—211
2 Andreu F.
Costa,
Seng Thipphavong,
Thomas Arnason,
Ashleigh E.
Stueck,
Sharon E.
Clarke.
Fat-Containing Liver Lesions on Imaging: Detection and Differential Diagnosis.
AJR 2018; 210:68–77
3 Hughes Cassidy F,
Yokoo T,
Aganovic L,
Hanna RF,
Bydder M,
Mid-delton MS,
et al.
Fatty liver disease: MR imaging techniques for the detection and quantification of liver...