Learning objectives
Review the fat-containing lesions of the liver.
Describe the main findings of each one and their significance.
Discuss the role of imaging in the diagnosis and differential in a fat-containing liver lesion.
Background
The group of liver lesions containing fat is wide including benign and malignant.
The fat may be present as macroscopic fat or intracellular lipid.
Ultrasound (US) is usually the first approach of liver lesions.
The fat usually appears hyperechoic at US and,
as the fat attenuates more than normal liver parenchyma,
partial acoustic shadowing may occur deep to fat-containing lesions [1].
However hyperechogenicity may be found in non-fat-containing lesions and subsequent characterization with CT,
MRI or even biopsy is usually necessary.
Macroscopic fat-containing lesions are...
Findings and procedure details
Benign liver lesions containing fat are common and include:
Hepatic steatosis,
which can be diffuse or focal,
is often seen.
The typical locations (periligamentous or periportal) and the absence of “mass effect” usually help in recognizing focal steatosis.
(Fig. 1) However,
multifocal nodular steatosis with patchy focal fat deposition may simulate metastatic disease at US or CT [4].
The use of GRE with in-phase and opposed-phase imaging allows a correct diagnosis.
(Fig. 2)
Adenoma is a benign,
encapsulated neoplasm that usually occurs in young women...
Conclusion
Fat-containing liver lesions include a heterogeneous group of tumors with variable histologic,
imaging findings and prognostic.
The identification of fat in a lesion is important to the diagnosis.
The characteristics of the fat component along with the other imaging features help in narrowing the differential diagnosis.
Although CT and US can sometimes show the presence of fat,
MRI is the most specific and useful technique in demonstrating both microscopic and macroscopic fat.
References
1.
Heinz-Peer G,
Oettl C,
Mayer G,
Mostbeck GH.
Hypoechoic perirenal fat in renal transplant recipients.
Radiology 1994; 193:717–720.
2.Mathieu D,
Paret M,
Mahfouz AE,
et al.
Hyperintense benign liver lesions on spin-echo T1-weighted.
MR images: pathologic correlations.
Abdom Imaging 1997; 22:410 – 417.
3.Delfaut EM,
Beltran J,
Johnson G,
Rousseau J,
Marchandise X,
Cotten A.
Fat suppression in MR imaging: techniques and pitfalls.
RadioGraphics 1999; 19:373–382.
4.Kemper J,
Jung G,
Poll LW,
Jonkmanns C,
Lu- then R,
Moedder U.
CT and MRI findings in...