Fractal Analysis of Cerebral Blood Flow Distribution in Alzheimer’s Disease

Journal of Nuclear Medicine

Akihiko Nebu¹  Junpei Ikezoe¹  Yoshifumi Sugawara¹  Hitoshi Miki¹  Takanori Kikuchi¹  Manabu Ikeda¹  Michinobu Nagao¹  Kenya Murase¹  Ryuji Fukuhara¹ 

[1] Departments of Radiology and Neuropsychiatry, Ehime University School of Medicine, Ehime; and Department of Medical Engineering, Division of Allied Health Sciences, Osaka University Medical School, Osaka, Japan Departments of Radiology and Neuropsychiatry, Ehime University School of Medicine, Ehime; and Department of Medical Engineering, Division of Allied Health Sciences, Osaka University Medical School, Osaka, Japan Departments of Radiology and Neuropsychiatry, Ehime University School of Medicine, Ehime; and Department of Medical Engineering, Division of Allied Health Sciences, Osaka University Medical School, Osaka, Japan

关键词: fractal analysis;    cerebral blood flow;    Alzheimer’s disease;    SPECT;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

This study describes a method for quantifying cerebral blood flow (CBF) distribution in Alzheimer’s disease (AD) from SPECT images obtained with 99mTc-hexamethylpropyleneamine oxime (HMPAO) by 3-dimensional fractal analysis (3D-FA). Methods: HMPAO SPECT was performed on 68 patients with probable AD and 14 healthy control subjects. We delineated the CBF images using 4 cutoff levels (35%, 40%, 45%, and 50% of the maximal voxel radioactivity) and measured the total number of voxels in the areas surrounded by the contours obtained with each cutoff level. We calculated fractal dimensions from the relationship between the total number of voxels and the cutoff levels transformed into natural logarithms. Results: The fractal dimensions (mean ± SD) for patients with probable AD and healthy subjects were 0.74 ± 0.33 and 0.52 ± 0.09, respectively. A significant difference in the fractal dimension was found between groups (P = 0.001). Statistically significant correlations were obtained between the fractal dimension and the Mini-Mental State Examination score (r = −0.598; P < 0.0001) and between the fractal dimension and the AD Assessment Scale (r = 0.670; P < 0.0001). The fractal dimensions for subjects with clinical dementia rates (CDRs) of 0, 1, 2, and 3 were 0.52 ± 0.09, 0.63 ± 0.21, 0.77 ± 0.23 (P < 0.05 vs. the group with a CDR of 1), and 1.43 ± 0.49 (P < 0.0001 vs. the group with a CDR of 2), respectively. Conclusion: Quantification of CBF distribution on SPECT images in AD was possible using 3D-FA. The fractal dimension was well correlated with the cognitive impairment, as assessed in neuropsychologic tests. 3D-FA may be a useful method for objectively evaluating the progression of AD.

【 授权许可】

Unknown