title: Heterogeneity of cerebral blood flow in frontotemporal lobar degeneration and Alzheimer's disease.
abstract: This study was designed to quantify the heterogeneity on cerebral blood flow single-photon emission tomography (SPET) images in frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD) using a three-dimensional fractal analysis. Twenty-one FTLD patients, 21 AD patients and 11 healthy controls underwent technetium-99m hexamethylpropylene amine oxime SPET scanning. Patients with FTLD and AD matched for sex, age and the severity of dementia as estimated with the Clinical Dementia Rating and were determined to be in the early stage of illness. We delineated the SPET images using a 35% cut-off and a 50% cut-off of the maximal voxel radioactivity and measured the number of voxels included in the contours of two different cut-offs. The fractal dimension (FD) was calculated by relating the logarithms of the cut-offs and the numbers of voxels, and it was defined as the heterogeneity of the cerebral perfusion. We divided the SPET images into two sets, anterior and posterior, with equal numbers of coronal SPET slices. We calculated total FD, anterior FD and posterior FD for total, anterior and posterior SPET images. Anterior FDs for FTLD and AD were 1.55 +/- 0.34 and 1.24 +/- 0.19 (P = 0.0002). The ratios of anterior to posterior FD for FTLD and AD were 1.81 +/- 0.41 and 1.32 +/- 0.14 (P < 0.0001). Use of the anterior FD and the ratio of anterior to posterior FD separated FTLD patients from AD patients and controls with a sensitivity of 85.7% and a specificity of 93.8%. Anterior FD and the ratio of anterior to posterior FD may be useful in distinguishing FTLD from AD.
authors.affiliation: Department of Radiology, Matsuyama Medical Center for Cancer and Cardiovascular Disease, Matsuyama-City, Ehime, Japan. minagao@ehime.med.or.jp
authors.forename: Michinobu
authors.initials: M
authors.lastname: Nagao
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Sugawara
authors.forename: Manabu
authors.initials: M
authors.lastname: Ikeda
authors.forename: Ryuji
authors.initials: R
authors.lastname: Fukuhara
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hokoishi
authors.forename: Kenya
authors.initials: K
authors.lastname: Murase
authors.forename: Teruhito
authors.initials: T
authors.lastname: Mochizuki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Miki
authors.forename: Takanori
authors.initials: T
authors.lastname: Kikuchi
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003704:Dementia / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003937:Diagnosis, Differential; D005260:Female; D017709:Fractals; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime