Evaluation of the corpus callosum of patient with Alzheimer's disease by using magnetic resonance diffusion tensor imaging

The purpose of the present study was to evaluate the fractional anisotropy (FA) and the number and the length of the fibers of three-dimensional fiber tractography based on a magnetic resonance diffusion tensor image (DTI) of the corpus callosum (CC) in patients with Alzheimer's disease (AD) in patients. The DTI was obtained in 30 patients with AD for five divided regions of the CC (mean age 77.4 ± 6.6 years, 20 females, 10 males). In addition, 30 patients with mild cognitive impairment (MCI) (mean age 71.3 ± 8.9 years, 17 females, 13 males) and 12 normal senile (NS) patients (mean age 68.9 ± 7.3 years, 6 females, 6 males) were studied using the same parameters. A single-shot spin echo planner imaging (EPI) pulse sequences was used at 3.0 Tesla. The region of interest in the midsagittal area of the CC was divided into five sections: genu, anterior midbody, posterior midbody, isthmus and splenium. The results showed in the patients with AD that the FA values were significantly decreased in all regions (P < 0.05) except for the isthmus (P = 0.187). In addition, the number of tracked fibers did not significantly differ among all regions (P > 0.05), and the lengths of the tracked fibers were decreased significantly only at the isthmus (P = 0.003). In the present study, we demonstrated that the isthmus in the CC showed a possibility of being an important assessment of anatomical bio-marker in the patients with AD and might help in brain diseases research using fiber tractography of the CC.