Figure 1. Pre-processing—improving information content. Image (a) shows a binding potential map of [¹¹C]raclopride in the brain of a normal subject. While the desired endpoint of the coregistration would most likely be the ability to fuse this with its corresponding MRI, the information content of the image is insufficient to give a good result. Image (b) shows a summed image of the whole dynamic scan used to calculate image (a). This now contains enough information to achieve satisfactory calculation of the transformation parameters which can then be applied to the binding potential map.