43. Quantitative Estimation of Brain Atrophy and Function with PET and MRI Two-dimensional Projection Images
Hinako Toyama, Reiko Saito, Koji Uemura, Kenji Ishii, Michio Senda and Akihiko Uchiyama
Keywords: brain atrophy, PET, MRI, corticobasal degeneration
The purpose of this paper is to estimate the brain atrophy and the decline in brain function objectively and quantitatively.
Two-dimensional projection images of PET and MRI were made from the 3D transaxial images by using the mollweide method which keeps the area of the brain surface. The sulcus is extracted automatically by means of K-means clustering the correlation image between MRI and CBF (FDG) PET images. the rate of atrophy is calculated from the ratio of the extracted sulcus to the area of 2D-brain-surface of MRI. the cerebral function (such as blood flow or glucose metabolic rate), is calculated from the cerebral cortex area except the sulcus in the PET image, and then the relationship between atrophy and function is evaluated.
This method is applied to two groups, the young and the aged normal subjects, then the relationship between the age and the rate of atrophy or the cerebral blood flow is investigated. This method is also applied to two groups of the normal control and the corticobasal degeneration patients, the relationship between the disease and the rate of atrophy or the functional disorder is investigated.
Significantly higher values of brain atrophy and lower values of CBF were obtained for aged group and the larger SDs were shown for CBF in young group and for brain atrophy in aged group. Almost same values of brain atrophy rate were estimated by using both images of CBF and glucose metabolism images.
A new method was proposed to estimate quantitatively and objectively the brain atrophy and function from PET and MRI. This method was evaluated in the normal subjects and in patients with corticobasal degeneration.