Predicting the performance of gamma-ray imaging devices in the task of tumor detection

A method for predicting the tumor-detection performance of gamma-ray imaging devices is described. Although the method can be used to evaluate any imaging system, including gamma cameras, it is used here to predict the relative performance of different designs of an intraoperative imaging probe. The method consists of specifying a task to be performed, calculating the point response function of each imaging system being considered, simulating the images produced by each system for the task, and calculating a figure of merit from the simulated images. The calculated figure of merit is the Hotelling trace. For the task of detecting a small (0.5-cm-diameter) tumor located 1 cm from the face of the parallel-hole collimator of an imaging probe, it is found that the best collimator bore length of the systems considered depends on the spatial distribution of the background activity. A very short (0.25-cm-long) bore is best if the tumor is embedded in uniform background activity, while a longer bore (0.50 cm long) is best if the spatial distribution of background activity is nonuniform.<
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