Proton transverse relaxation rate (R2) images of liver tissue; mapping local tissue iron concentrations with MRI [corrected]

Abstract

Proton transverse relaxation rate (R(2)) imaging measurements were made on post mortem iron-loaded human liver tissue samples (both intact and dissected into approximately 1-cm cubes) from a single subject. Iron concentrations for the dissected samples as measured by atomic absorption spectrometry varied from 10.8 to 23.3 mg Fe.g(-1) dry tissue. A significant linear correlation between the mean R(2) and iron concentration of each sample was found (r = 0.95). In addition, regions of liver tissue with micronodular cirrhosis exhibited lower R(2) values, corresponding to the displacement of iron by fibrotic septa. The cirrhotic tissue was clearly identified as a separate peak in the R(2) distribution of the tissue. The relaxivity of the iron did not appear to depend on the microarchitecture of the tissue.