Computed detection and quantitative morphometry of Alzheimer senile plaques.

Senile plaques (SP) are the most characteristic neuropathologic lesions of Alzheimer's disease (AD) and studies of plaque cortical distribution, density, and morphology may lead to new information about the origin and pathogenesis of this disease. We have developed an automated computer image analysis program to detect SP (including diffuse and mature forms) and to measure SP size, shape, and fractional area or load in digital micrographs of silver-stained tissue sections. The plaques are detected with adaptive thresholding, requiring no user interaction. Measures of SP size, morphology, and load are readily calculated from the pixel values in the detected SP features. These measurements are achieved accurately and exhaustively, and this method offers an alternative to manual SP counting. We demonstrate its application to 4 cases spanning the full range of the severity of the disease.