Tabletop device tracks water diffusion in the liver to detect fibrosis
An accumulation of fat in liver cells can lead to serious problems, including inflammation, jaundice and, in more severe cases, cirrhosis and liver failure. But fatty liver disease is difficult to detect before symptoms such as fatigue and abdominal swelling start to appear, so researchers are working on ways to diagnose the condition earlier in the piece. A new device from a team of MIT scientists could offer a way forward, with the ability to non-invasively detect signs of the condition in mice with a high degree of accuracy.
As our liver cells start to store too much fat and become inflamed, they begin to build up scar tissue, a condition known as liver fibrosis. This is a precursor to the conditions mentioned above, and currently the only way fibrosis can be conclusively diagnosed is via biopsy, which is invasive and can be inaccurate as the scarring may not be equally distributed in all tissues across the organ.
MIT scientists may have found an easier way to check for liver fibrosis, by adapting a technology originally developed to measure hydration levels in patients undergoing dialysis. To analyze fluid levels in the skeletal muscle, the device uses nuclear magnetic resonance (NMR) to detect changes in the magnetism of hydrogen atoms of water in the tissue.
As water moves more slowly when it interacts with fatty tissue or fibrosis, the team suspected that the detector could be used to pick up signs of liver disease by tracking how water diffuses through the organ.
“If you watch how the magnetization changes, you can model how fast the protons are moving,” says senior author Michael Cima. “Those cases where the magnetization doesn't go away very fast would be ones where the diffusivity was low, and they would be the most fibrotic.”
The team used the NMR detector, which is small enough to place on top of a table, to scan to depths of around 6 mm (0.23 in) below the surface of the skin of mice. This was enough to analyze their liver and the skeletal muscle of the rodents, with the technique proving capable of identifying fibrosis with an accuracy of 86 percent, and fatty liver disease with an accuracy of 92 percent. Applying it to human liver tissue, it detected fibrosis with 93-percent accuracy.
From here, the researchers are working on a version of the device that will be able to penetrate deeper into the skin, which they say will be necessary for testing on human patients. If this works, it could offer a way of detecting fibrosis in its early stages, leaving the door open for more effective treatments.
“Since it’s a noninvasive test, you could screen people even before they have obvious symptoms of compromised liver, and you would be able to say which of these patients had fibrosis,” says Cima.
The research was published in the journal Nature Biomedical Engineering.