Research On The Method Of Modeling And Analyzing The Morphology Of Hippocampus In Alzheimer’s Disease

Alzheimer’s disease is one of the most common diseases in the elderly.Its main symptom is the decline of cognitive function and the gradual loss of living ability.Researches have shown that Alzheimer’s disease can lead to brain structural distortion.The most typical brain structure is the hippocampus.Therefore,the study of hippocampal morphological changes in Magnetic Resonance Image is conducive to the early diagnosis of the disease and the further study of the mechanism of the occurrence and progression of the disease.At present,the methods of hippocampal morphology of Alzheimer’s disease in magnetic resonance imaging only describe the shape of hippocampus from volume or surface parameters.These methods are lacking in refinement.In order to overcome the shortcomings,an analysis method based on Skeletal-representation(S-rep)model was constructed in this paper.The S-rep model of hippocampus was obtained by the mapping relationship established by mean curvature flow between hippocampus and ellipsoid.The S-rep model effectively described the morphological features of the hippocampus by using scale factor,spokes length,spokes direction and skeleton atoms location.In addition,this paper proposed a comparison method of s-rep average skeletons between groups.By using logarithmic mapping,two-dimensional and high-dimensional spherical spatial data analysis methods,the distribution trend of S-rep parameters in non-Euclidean space was fitted.The average S-rep model within the group was obtained to realize skeleton fusion.Using this method,we compared the hippocampal morphology of different age subjects to describe the hippocampal atrophy mode of normal aging.The results verify the S-rep model.Compared with the existing methods,the S-rep model can describe the morphological features of hippocampus more precisely.In this paper,we compared and analyzed the differences of hippocampal morphology between normal control subjects and Alzheimer’s disease subjects.The results showed that the morphological aberrations of the hippocampus were concentrated at the head and tail,and it was more severe in the left hippocampus.Finally,through the comparative analysis of different stages and types of Alzheimer’s disease spectrum subjects,we found that two years before the diagnosis of conversion,the left hippocampus had already appeared specific pathological changes,such as the inward contraction of the skeleton point and the change of surface normal vector direction.At the time of converted diagnosis,the hippocampal deformation pattern of Alzheimer’s disease appeared.The results revealed the track of human brain morphological changes of hippocampus in Alzheimer disease spectrum.In this paper,an analysis model of hippocampal morphology in Alzheimer’s disease was established based on the comparison of average s-rep among groups.The S-rep model can effectively represent the morphological features of the hippocampus,and it realized the comparative analysis between subjects and groups.The improvement of the spatial accuracy and interpretability in morphological analysis helped to reveal the hippocampal body deformation pattern of Alzheimer’s disease spectrum.This provided a detailed and effective research basis for early diagnosis and pathological research of Alzheimer’s disease.