American Board of Pathology (ABPath) Practice Test

Focal fatty sparing in the liver occurs when certain areas of the liver are less affected by fatty infiltration compared to the surrounding liver tissue. This phenomenon manifests as regions that appear less echogenic (hypoechoic) when viewed on ultrasound. The fat-containing areas typically exhibit increased echogenicity, while the spared areas retain a relatively lower echogenicity, making them appear darker on the ultrasound image against the brighter, fatty regions. Recognizing this contrast is essential in interpreting liver imaging correctly.

Other terms, such as hyperechoic or isochoic, describe different echogenic characteristics but do not accurately represent focal fatty sparing in the context of surrounding liver tissue. Enhanced echogenicity would imply greater brightness, which does not apply to the hypoechoic areas standing out due to their lower fat content. Understanding these echogenic patterns is crucial for diagnosing various liver conditions, including steatosis and diseases leading to altered liver architecture.