Computer detection and display of focal lesions on scintiscans

Both photoscans and lineprinter-produced digital scans are shown to have disadvantages in the detection of small focal lesions. These lesions produce a local concavity or convexity in the count-rate profile over the organ. A display system is described using an off-line digital computer which searches for structures whose dimensions are comparable to the spatial resolution of the scanning system, then applies a simple statistical test of the significance of these structures. By this means, most of the large-scale features of the scan are filtered out, and the information finally displayed on a lineprinter concerns mainly those structures which are difficult to detect with conventional displays. The results of both phantom and clinical studies are presented, illustrating the ability of this system to increase the efficiency and accuracy of detection of small lesions and to simplify interpretation.