Quantitative analysis of whole body autoradiogram using a computer-assisted image analyzer

Abstract

A computer-assisted image analyzer system for the determination of tissue drug concentration using whole body autoradiograms is described. An image of a whole body autoradiogram was taken by the video camera, and the shading was corrected by the ratio correction procedure. Calibration curve was obtained by using standard tissue sections which contained known concentration of radioactivity. The non-linear relationship between mean gray values obtained by the video analysis method and radioactivity concentration in corresponding tissues was corrected by the linearization process. These correction procedures were effective to solve the problems of video camera-based image analysis of autoradiogram.
By using this video analysis method, indomethacin concentration in rat tissue after p.o. and i.v. administration was determined and was compared with that obtained by scintillation counting method. Both methods gave almost identical results in most of tissues, however, blood level of a drug affected the determination of its concentration in capillary rich tissues in the video analysis method.