Fatty Liver Infiltration Explained

Fatty liver infiltration, also known as focal fatty liver, refers to a condition where fat accumulates unevenly in the liver, rather than spreading uniformly throughout the organ. This type of fat distribution is detectable through imaging techniques such as ultrasound or CT scans and presents distinct visual characteristics.

During an ultrasound examination, fatty infiltration may appear as areas of reduced echogenicity, where the liver's overall echo pattern seems less dense. In more severe cases, the liver's vascular structure may become less visible, indicating a higher degree of fat accumulation.

On a CT scan, the diagnosis is often based on the comparison of liver and spleen attenuation values. Normally, the liver has a CT Hounsfield Unit (HU) value close to that of the spleen. A liver-to-spleen CT value ratio between 0.7 and 1.0 typically indicates mild fatty liver disease, while a ratio between 0.5 and 0.7 suggests moderate disease. A ratio of 0.3 to 0.5 indicates severe fatty infiltration, and values below 0.3 point to extreme severity.

It's important to note that localized fatty liver can sometimes mimic liver tumors or other space-occupying lesions. Therefore, accurate diagnosis is crucial. In some cases, further tests such as contrast-enhanced CT scans or a liver biopsy may be recommended to rule out other serious conditions.

In conclusion, understanding fatty liver infiltration involves both imaging interpretation and clinical evaluation to differentiate it from more concerning liver pathologies and to determine the appropriate course of action.