The role of brain structural magnetic resonance imaging in the assessment of hippocampal subfields in Alzheimer's disease

Background Volumetric MR neuroimaging can visualize the pattern of hippocampal subfield atrophic changes in AD. This can be used as a biomarker in early diagnosis of AD and allow early treatment to improve memory, behavioral symptoms, and delay the cognitive deterioration. The aim of this work is to assess the role of the volumetric study of different hippocampal subfields as a post-processing technique of structural MR imaging in patients with Alzheimer's disease of different severity of cognitive functions. The regional ethics committee approved the study and written informed consent was obtained from all participants. In the duration from 2016 to 2018, a cross-sectional study was conducted on 30 patients (17 males and 13 females) and 15 healthy elderly controls (9 males and 6 females) referred to the Radiodiagnosis Department from the Neuropsychiatry Department. Patients were diagnosed with AD by clinical examination and using the Mini Mental State Examination (MMSE) and the Clinical Dementia Rating scale (CDR) as a measure of general cognitive performance. Results CA1 and subiculum subfields were significantly reduced in size in patients with Alzheimer's disease in relation to the age-matched control group (P < 0.05). This finding was positively correlated with the MMSE score and negatively correlated with CDR clinical tests. No significant atrophy was found among other hippocampal subfields in the patients' group. Conclusion This study proposed a new approach to detect atrophy in hippocampal subfields, using MR volumetric study of high-resolution T1 images, that can be used as a biomarker in the diagnosis of AD patients and differentiating them from elderly control subjects which is important in early diagnosis of AD and hence the proper treatment to improve the prognosis of the cognitive function.