Figure 10.

A comparison of reconstructions with fixed-geometry and adaptive systems. (a) Central slice of a simulated 3D phantom with six hot cylinders (diameter of 0.625 mm and edge-to-edge separations of 0.625 mm) embedded in a colder phantom (diameter 27.5 mm). The activity ratio is 10:1. (b) Reconstruction of noiseless phantom data for a fixed-geometry system. (c) Reconstruction of noiseless phantom data for the adaptive system. (d) Reconstruction of noise-present phantom data (10 000 000 mean total projection counts) for a fixed-geometry system. (e) Reconstruction of noise-present phantom data (4 001 000 mean total projection counts) for the adaptive system. While the adaptive system displays more artifacts in its reconstructions, identification of the six hot cylinders is much improved over the fixed-geometry system.