Computed Tomography is one of the most popular diagnostic tools available to medical professionals. However, its diagnostic power comes at a cost to the patient- significant radiation exposure. The amount of radiation exposure is a function of the number of angular measurements necessary to successfully reconstruct the imaged volume. Compressed sensing on the other hand is a technique that allows one to reconstruct signals from a very limited set of samples provided that the target signal is compressible in a transform domain. Combining the two gives clinicians the benefits of CT while at the same time limiting the risk posed by excessive radiation. In this work we formulate the computed tomography reconstruction problem within a compressed sensing framework using partial pseudo-polar Fourier transform. Simulated results indicate that the number of angular projections and hence the associated radiation can be cut by a factor of 4 or more without noticeable loss of image quality.
Siemens Corporate Research, September 2008