[1H-MRSI of Alzheimer's disease]

To evaluate neuronal change in the neocortex of the patients with Alzheimer's disease in early stage, proton MRSI study was performed in 13 probable AD patients and 6 healthy volunteers and the change of NAA, a putative neuronal marker, between the temporal cortex and the white matter including basal ganglia was analyzed. Proton MRSI data were measured with 3D-FT-CSI method, using spin echo method with TE = 135 ms. Two directional 16 x 16 phase encodings were applied on the field of 18 x 18 x 1.5 cm3. One voxel size was 1.9 cm3. Out of thirteen probable AD patients, 7 patents, who were considered in early stage, showed low NAA levels in the temporal neocortex without NAA change in the white matter including basal ganglia. Six patients, who were considered in more advanced stage, showed low NAA levels in both regions. NAA decrease in neocortical area is considered to be a good indication of AD in early stage at the examination with proton MRSI.