FIG. 1.

A small animal Compton camera simulated in this study. The dimensions of the CZT scatter detectors were 5 × 5 × 1 cm and the absorption detectors were 10 × 10 × 1 cm. The fifth pair of the CZT detectors was placed at the back of the field-of-view (FOV), as marked with dashed lines. Each detector panel consisted of four 2.5 mm thick layers (denoted by thick black lines on the right pair of detectors). Three different distances d between the scatter and absorption detectors (measured from the center to the center of the detectors) were investigated: 30, 50, and 70 mm. The phantom is positioned off-center inside the camera.