Diffusion tensor imaging correlates with proton magnetic resonance spectroscopy in posterior cingulate region of patients with Alzheimer's disease.

BACKGROUND/AIMS: To compare proton magnetic resonance spectroscopy ((1)H-MRS) and diffusion tensor imaging (DTI) findings in the posterior cingulate regions in patients with Alzheimer's disease (AD).

METHODS

17 patients with mild AD, 20 with moderate to severe AD and 20 cognitively normal aging subjects (CN) underwent single-voxel MRS and DTI examinations. A region of interest was positioned in the posterior cingulate regions. Ratios of N-acetylaspartate (NAA), myo-inositol (mI), and choline to creatine (Cr) were measured. Mean spectroscopy data and DTI values (fractional anisotropy, FA, and mean diffusivity, MD) were analyzed with nonparametric testing.

RESULTS

The group with mild AD showed a significantly lower FA value in the left posterior cingulum compared to CN. The group with moderate to severe AD revealed significantly decreased FA values and increased MD values in both the left and right cingulum compared to the group with mild AD. Partial correlation analysis revealed a positive correlation between mI/Cr and left-side FA values in the group with mild AD and a negative correlation between NAA/Cr and right-side MD values in the group with moderate to severe AD.

CONCLUSION

There are different regional and temporal patterns in AD, resulting from gliosis or axonal loss. Combining MRS with DTI could provide valuable information to better understand the AD process.