Non-elastography key points:
- Liver biopsy is the current reference standard for diagnosis of hepatic fibrosis.
- Blood tests are valuable as an adjunct but are not the primary method of assessment.
- The most commonly used fibrosis grading system is METAVIR.
- Cross-sectional imaging diagnostic features: anatomic distortion, changes in parenchymal attenuation and signal intensity/echo texture, alterations of dynamic contrast enhancement.
- Anatomic signs of cirrhosis include surface nodularity, segmental hypertrophy or atrophy.
- Useful diagnostic signs are enlarged. Elarged portal hilar space, and large gallbladder fossa sign and posterior hepatic Notch sign. A 100 percent specific sign is the ratio of the caudate lobe width to the right hepatic width however this is prone to serious interobserver variability.
- Elastography is currently only practical in the ultrasound setting. Cut offs for elastography are manufacturer specific and vary with the technique. Scoring is done using the METAVIR system ranging from F0 to F4 This is based on shear wave elastography in most cases with a single manufacturer using transient elastography.
- MR elastography techniques have been developed but are not in widespread use and are probably impractical in the community setting.