Simultaneous quantification of liver fat and iron using MRI: Comparing the performance of different MRI signal models for the quantification of liver fat and iron

[Truncated] Liver biopsy for the quantification of fat and iron in the liver has been replaced in recent years with non-invasive methods such as magnetic resonance imaging (MRI). Reasons for this include the risks associated with an invasive procedure such as biopsy, the subjective nature of the pathologist’s assessment of fat and iron, and the fact that the biopsy tissue sample represents only a tiny fraction of the liver.

It is not uncommon for patients with fatty liver to also have iron overload, and vice versa. Therefore methods that quantify either fat or iron, or both, must not be confounded by the presence of the other. MRI signal models currently used for the quantification of fat include the transverse relaxation rate term R^*₂, in order to address a potential confounder. Since these signal models are already calculating R^*₂, and it has been observed that R^*₂ has a linear relationship with liver iron concentration, these signal models have been natural candidates for the simultaneous quantification of liver fat and iron.