A new technique for measuring the hardness or elasticity of the liver has been developed by Mayo Clinic researchers using magnetic resonance imaging (MRI). Initial tests show promise for this technology, MR Elastography (MRE), for detecting liver fibrosis, a common condition that can lead to incurable cirrhosis if not treated in time.
Traditionally, liver fibrosis is usually diagnosed using needle biopsies, which can involve complications and may be inaccurate due to sampling errors. The new technology promises to provide an accurate, painless, and lower risk alternative to liver biopsy and may have implications for diagnosing cancer. These research findings appeared in the journal Radiology.
"This is potentially an important diagnostic advance, since conventional imaging techniques, such as CT, MRI and ultrasound are not capable of identifying liver fibrosis prior to the onset of cirrhosis," says Richard Ehman, M.D., Mayo researcher and lead investigator on the study.
The healthy liver is very soft compared to most other tissues and especially compared to a liver with cirrhosis, which is rock hard. The development by Dr. Ehman and his colleagues applies vibrations to the liver and then utilizes a modified form of MRI to obtain pictures of the mechanical waves passing through the organ. The imaging can be accomplished in as little as 20 seconds. The wave pictures are then processed to generate a quantitative image of tissue stiffness -- called an elastogram.
Researchers compared results of the process on 12 patients with biopsy-proven liver fibrosis with those of 12 healthy participants. This pilot trial of MRE showed strikingly elevated stiffness in patients with fibrosis and that the stiffness increased with the progression of the condition.
Impact of the Research
The availability of a reliable, non-invasive method for detecting liver fibrosis could lead to early diagnosis -- in patients considered at risk for liver disease -- and increase their chances for successful treatment. For example, 170 million people worldwide are infected with chronic hepatitis C and a significant number will develop cirrhosis, which is untreatable. Even if some risk factors are identified, there is no way to predict which patients will develop fibrosis, and successive liver biopsies in all these patients aren't possible. Non-invasive monitoring with MRE of those at risk would detect the problem early and help assess the effect of treatments.