Quantitative analysis of T2 signal intensities in Alzheimer's Disease

Hypointensities (focal areas of decreased-signal intensity) have been reported on T2 weighted magnetic resonance images (MRI) in normal aging and in some neurological disease processes. Increased concentrations of iron have been suggested as one cause of these hypointensities. In Alzheimer's Disease, data suggests that there is both a disruption in iron metabolism as well as the presence of T2 hypointensities. We endeavored to determine if the decreased signal intensities could be quantitatively determined and, if so, in what regions, in an effort to establish a non-invasive biological marker and diagnostic aide. We performed a quantitative analysis of the T2 signal intensities in 13 MRIs from AD patients and 16 age- and sex-matched control subjects. We found that while there were statistically significant differences in the intensities of the putamen and red nucleus, these differences were small. We were unable to detect differences in intensities in a whole slice or the frontal lobe. To our knowledge this is the first quantitative comparison of MRI signal intensities in Alzheimer's Disease.