{'fraction_non_alphanumeric': 0.03143418467583497, 'fraction_numerical': 0.0137524557956778, 'mean_word_length': 5.52991452991453, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Evaluation of Posterior Cingulate Gyrus by Diffusion Tensor Imaging in Alzheimer’s Disease Patients Compared with Normal Control Subjects

Objective : Posterior cingulate gyrus atrophy is found in early clinical stage of Alzheimer’s disease (AD) patients. 1 Diffusion tensor imaging (DTI) can be used for evaluating microstructure change in brain parenchyma. 2 Our objective was to compare the microstructural change at posterior cingulate gyrus between AD patients and normal control subjects by using DTI. Methods : The retrospective review of 23 AD patients, diagnosed by NINCDS-ADRDA with available MRI data including DTI, and 19 normal control subjects was performed. The DTI parameters of posterior cingulate gyrus of each group were analyzed and compared. Results : The mean diffusivity (MD), axial diffusivity and radial diffusivity (RD) of posterior cingulate gyrus were significantly increased in AD patients compared with normal control subjects (p-value <0.001, <0.001, <0.001, respectively). The fractional anisotropy (FA) was slightly decreased in AD patients compared with normal control subjects but did not reach statistical significance (p value=0.71). Conclusion : Microstructural change at posterior cingulate gyrus demonstrated by DTI parameters including MD, axial diffusivity and RD were significantly different between AD patients and normal control subjects.  These results were probably helpful for early diagnosis, evaluation, and follow up of the AD patients as correlate with clinical findings.