Fatty liver is often detected through a combination of tests. There isn't one single definitive test, but a diagnosis typically involves several approaches.
Diagnosing Fatty Liver: A Multi-pronged Approach
Several methods are used to detect and diagnose fatty liver disease. These include blood tests, imaging techniques, and in some cases, a liver biopsy.
1. Blood Tests:
- Liver Function Tests (LFTs): These tests measure levels of liver enzymes like alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in your blood. Elevated levels can indicate liver inflammation, a common sign of fatty liver. These tests are often part of a routine checkup and may be the first indication of a problem. [Referencing multiple sources stating blood tests, specifically LFTs, are crucial for initial diagnosis.]
2. Imaging Tests:
- Ultrasound: This non-invasive imaging technique uses sound waves to create images of the liver. It can detect fatty deposits in the liver but may not always identify mild cases of fibrosis (scarring). [Multiple sources cite ultrasound as a primary imaging technique.]
- Computed Tomography (CT) Scan: A CT scan uses X-rays to create detailed images of the liver. It's more sensitive than ultrasound in detecting fatty infiltration, and better at identifying milder fibrosis, but still might not give a completely accurate representation of disease severity. [Referencing Mayo Clinic and other sources that mention CT scans as a diagnostic tool.]
- Magnetic Resonance Imaging (MRI): MRI provides even more detailed images of the liver than a CT scan. It's particularly useful for detecting and assessing the extent of liver fibrosis (scarring). While better than CT for identifying fibrosis, it might still not be entirely conclusive. [Mayo Clinic and other sources mention MRI as a diagnostic option, particularly for fibrosis detection.]
3. Liver Biopsy:
- Liver Biopsy: This invasive procedure involves removing a small tissue sample from the liver for microscopic examination. It's considered the gold standard for diagnosing non-alcoholic steatohepatitis (NASH), a more severe form of fatty liver disease, and assessing the degree of fibrosis. While definitive, it's not a first-line test due to its invasive nature. [Multiple sources, including the NIDDK, highlight liver biopsy as the gold standard for diagnosis of NASH and fibrosis severity.]
Determining the Need for Further Testing
Testing for fatty liver is often prompted by elevated liver enzymes detected during routine blood tests or suspicion based on risk factors like obesity, diabetes, or high cholesterol. The choice of further testing depends on the individual's medical history and the results of initial blood tests.
