Ultrasound Terminology for Fatty Liver
The ultrasound examination for fatty liver is simply called a "liver ultrasound" or "hepatic ultrasound" - there is no special name for this test when evaluating for fatty liver disease 1, 2.
What the Test Actually Evaluates
Ultrasound detects fatty liver by identifying increased parenchymal echogenicity (brightness) of the liver tissue 3. The test is commonly ordered as:
- Abdominal ultrasound (includes liver evaluation) 2, 4
- Right upper quadrant ultrasound
- Liver ultrasound 5
Important Clinical Context
While ultrasound is widely used as the first-line screening modality for fatty liver in high-risk populations (diabetes, metabolic syndrome, obesity, elevated liver enzymes), you should understand its significant limitations 1, 2:
Critical Limitations to Know
- Ultrasound has poor accuracy for grading steatosis severity, with positive predictive values of only 47-62% in children, and similar limitations in adults 5
- Sensitivity drops dramatically when steatosis is less than 30% 1
- Cannot distinguish simple steatosis from steatohepatitis (NASH), as it cannot assess microscopic features like hepatocyte ballooning or inflammation 1, 2
- Cannot detect or stage liver fibrosis, which is the most critical prognostic factor 2
When More Accurate Imaging Is Needed
MRI with proton density fat fraction (MRI-PDFF) is the most accurate non-invasive method for detecting and quantifying liver fat, though it is not recommended as first-line due to cost and limited availability 1. Controlled Attenuation Parameter (CAP) via transient elastography provides quantitative steatosis assessment and can be examined simultaneously with liver stiffness measurement 1.
The European Association for the Study of the Liver recommends conventional ultrasound as first-line for monitoring hepatic steatosis in clinical practice despite its limitations, due to universal availability, real-time capability, low cost, and no radiation exposure 1.