RT Journal Article
SR Electronic
T1 Fractal Analysis of Cerebral Blood Flow Distribution in Alzheimer’s Disease
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1446
OP 1450
VO 42
IS 10
A1 Michinobu Nagao
A1 Kenya Murase
A1 Takanori Kikuchi
A1 Manabu Ikeda
A1 Akihiko Nebu
A1 Ryuji Fukuhara
A1 Yoshifumi Sugawara
A1 Hitoshi Miki
A1 Junpei Ikezoe
YR 2001
UL http://jnm.snmjournals.org/content/42/10/1446.abstract
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.