Characteristics Scanning of Brain Structure and Function Changes in Patients with Different Degrees of Alzheimer's Disease

Through the case control study on structural magnetic resonance imaging (sMRI) scanning, MR spectrum (MRS), and neuropsychological assessment of the intracranial structures of Alzheimer's disease (AD), patients of different degrees (early, middle, and late), the early clinical features, imaging features, and neuropsychological characteristics of patients with AD were analyzed to provide help for the early diagnosis of AD. The data of MR scanning of the brain, bilateral MRS scan of the hippocampus, thyroid function and other laboratory indicators, and neuropsychological evaluation analysis were collected in 50 patients who had been diagnosed with AD. According to CDR, 50 patients were divided into the early AD group and the middle and advanced AD group, with 23 patients in the early AD group and 27 patients in the middle and advanced AD group. Retrospective study was conducted to analyze the general conditions, medial temporal lobe atrophy (MTA) grading, and the metabolic changes of bilateral MRS in the hippocampus of patients in both groups, so did the mini-mental state examination (MMSE), activities of daily living scale (ADL), and other neuropsychological assessment results. Moreover, the comparative analysis was carried out. The results showed that the MTA grade of medial temporal atrophy increased with the progressive severity of the disease in both groups. A statistical test was conducted on the reduction of hippocampal volume in the two groups, and the P was less than 0.05. Therefore, the MTA scale was of great value in the diagnosis and staging of early AD. However, when the diagnosis of early AD was treated by MTA visual evaluation alone, there was 23.8% false negative diagnosis. If the judgment of early AD only depended on the metabolic changes of hippocampus MRS or MR scanning of intracranial structures, it was likely to cause false negative diagnosis. Therefore, the combination of MRS analysis and MR scanning of intracranial structures was favorable for the early diagnosis and treatment of AD. Combined with neuropsychological assessment, AD patients were staged more effectively, which greatly improved the accuracy of AD diagnosis in the early stage.