Global experts in diagnostic medicine, medical physics and image analysis
LiverMultiScan brings cT1, T2* and fat fraction together for the first time to support the assessment of chronic liver disease.
It uses magnetic resonance imaging (MRI) data to calculate images of proton density fat fraction, T2* and T1 in the liver. These parameters have been shown to correlate with histological measures of steatosis, hemosiderosis and fibrosis of the liver.
T1 and T2* are physical parameters which describe the ‘relaxivity’ of tissue in an induced magnetic field. The strong magnetic field in an MRI machine is used to excite water and fat molecules, which depending on their local environment, relax at different speeds. As they relax, they emit a signal which is used to create the T1 and T2* MR images.
T2* is influenced by iron deposits which act as small magnets, causing the signal to decay at a rate proportional to the iron concentration. Tissues with high iron typically have very small T2*s, whilst tissues with very low iron have high T2*s.
T2* and its related parameter R2* are used as biomarkers in the assessment of hepatic iron overload, or hemosiderosis.
T1 is influenced by the type and structural organisation of a tissue. Denser tissues such as fat have very low T1s, whilst tissues with a high water content such as muscle and the spleen have very high T1s. When tissue is inflamed or scarred (fibrotic), changes in the structural organisation of the tissue (tissue remodelling) mean that the water content increases and the T1 gets higher.
T1 is used as a biomarker the assessment of myocardial fibrosis. One major challenge of transferring this technology transfer from the heart to the liver is that more than 40% of liver disease patients have iron overload. This distorts T1 values, increasing the risk of misdiagnosis. Our patented technology uses the T2* image to correct for iron – producing our proprietary metric; cT1.
Inflammation and fibrosis are increasingly believed to be part of a continuum of disease progression.
Acutely inflamed tissue tends to have a higher water content and similarly, fibrotic tissue forms from structural modifications (e.g. increased extracellular volume), creating more space for water. A 2015 clinical study showed that the LIF score (closely related to T1) predicted clinical outcomes in patients with chronic liver disease.
The LIF score (LiverMultiScan Discover only)
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