PT  - JOURNAL ARTICLE
AU  - Michinobu Nagao
AU  - Kenya Murase
AU  - Takanori Kikuchi
AU  - Manabu Ikeda
AU  - Akihiko Nebu
AU  - Ryuji Fukuhara
AU  - Yoshifumi Sugawara
AU  - Hitoshi Miki
AU  - Junpei Ikezoe
TI  - Fractal Analysis of Cerebral Blood Flow Distribution in Alzheimer’s Disease
DP  - 2001 Oct 01
TA  - Journal of Nuclear Medicine
PG  - 1446--1450
VI  - 42
IP  - 10
4099  - http://jnm.snmjournals.org/content/42/10/1446.short
4100  - http://jnm.snmjournals.org/content/42/10/1446.full
SO  - J Nucl Med2001 Oct 01; 42
AB  - 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.