Attenuation correction in PET using consistency information

In this study we use the consistency conditions of the Radon transform to a id attenuation correction in PET. The conditions are used both for estimati ng the parameters of a uniform elliptical attenuation distribution (without any transmission measurements) and for correcting for patient motion betwe en the transmission and emission acquisitions. The results show that, for a uniform elliptical attenuation distribution, the reconstructed count densi ties obtained using attenuation correction based on the consistency conditi ons are within 1% of the true values. The method is shown to be fairly tole rant to the effects of photon counting statistics and to small non-uniformi ties in the attenuation distribution (such as skull attenuation). The resul ts also show that the consistency conditions may be useful in correcting fo r patient motion. The method is shown to effectively compensate for shifts in two dimensions using both simulated and experimental data.