Corrections for the Gamma Camera
Ideally as the camera rotates around 360 degrees, we would like the center of rotation to always project into the same hole in the collimator. We would expect also that the opposite cameras would be getting mirror images of each other. Unfortunately, due to the weight of the cameras, the mechanics of the rotating gears, and everyday wear and tear on the equipment, it is hard to get perfect results. Misalignments cause blurry reconstructed images.
Photons exponentially attenuate making acquisition of accurate tracer data difficult. Since the radiation from the parts of the body farthest away from the camera degrades before it reaches the detectors, this also distorts the data.
There are many other errors which come into play in using a gamma camera. However, for our purposes, correcting for these errors in the few real data samples we acquired was unnecessary. We are primarily concerned with understanding the reconstruction of images.