Liver SW Elastography 2019

Liver SW elastography has become increasingly available and more frequently performed over the last 5 years. We were one of the first and all GMI sonographers and I have gained significant experience performing and interpreting the test. Having a good relationship and getting valuable feedback from our local hepatologists has been very helpful.

The test/scan has reduced the number of liver biopsies required and provides a valuable screening tool for those with abnormal liver function tests, but it needs to be interpreted carefully and specifically within the individual clinical context. There are a number of pitfalls in performing the test and interpreting the results. When used in a screening setting we need to make sure that the right patients get further specialist advice and assessment. 

The table below broadly categorises the clinical implications of a SW elastography result which has been shown to be both valid (IQR/median <30%) and have reliable readings. The example of readings shown shows an acceptable IQR but only moderately reliable measurements (RMIs).

SW Elastography	Clinical Implications
<6 kPa	Normal
6-10kPa	Abnormal but generally excludes compensated advanced chronic liver disease. Follow-up needed.
10-15 kPa	Probable compensated advanced chronic liver disease
15-20 kPa	Compensated advanced chronic liver disease
>20kPa	Assess for oesophageal varices