Learning objectives
To describe the imaging features of hepatic steatosis and highlight the imaging patterns and pitfalls which this condition creates in the work-up and follow-up of patients being investigated and treated for malignancy.
Background
Hepatic steatosis or non alcoholic liver disease (NAFLD) is a common condition and it’s incidence has been reported in 10-35% of the population (1).
Histologically it is caused by triglyceride accumulation within the cytoplasm of hepatocytes (2).
The incidence has increased in recent decades in association with the increased prevalence of obesity within the population.
The condition creates a unique conundrum when imaging the liver,
as the sensitivity for detection of focal liver lesions in diffusely steatotic liver is reduced.
More than 10% of hepatic...
Findings and procedure details
Imaging features of diffuse hepatic steatosis.
Ultrasound:
CT:
MRI:
Hyper-echoic liver.(Fig1)
Hypo-attenuation of the liver parenchyma.
(Fig1)
T1: Increased signal.
The renal cortex appears hypo-echoic relative to the liver.
(Fig2)
Non-contrast CT: attenuation of the liver is >10Hounsfield units (HU) less than that of the spleen
T2: Mild increase in signal intensity less so than on T1.
Poor delineation of intra-hepatic echotexture.
(Fig1)
Contrast enhanced CT: Attenuation is >40HU less than that of the spleen.
(Fig3)
Opposed phase: Decreased signal intensity.
In-phase: Increased signal intensity....
Conclusion
Radiologists and clinicians need to be aware of the impact that hepatic steatosis can have on the imaging work-up of patients with malignancy and the limitations of imaging in these patients.
Radiologists need to impart to their oncological colleagues the pitfalls in evaluating patients for hepatic metastatic disease in the setting of background fatty liver changes.
References
1 Vernon G,
Baranova A,
Younossi ZM.
Systematic review: the epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults.
Aliment Pharmacol Ther 2011;34:274–85.
doi:10.1111/j.1365-2036.2011.04724.x
2 Hamer OW,
Aguirre DA,
Casola G,
et al. Fatty liver: imaging patterns and pitfalls.
Radiogr Rev Publ Radiol Soc N Am Inc 2006;26:1637–53.
doi:10.1148/rg.266065004
3 Bartolotta TV,
Taibbi A,
Picone D,
et al. Detection of liver metastases in cancer patients with geographic fatty infiltration of the liver: the added value of contrast-enhanced sonography.
Ultrasonography 2017;36:160–9....