Incorporating MRI region information into SPECT reconstruction using joint estimation

Single Photon Emission Computed Tomographic im-ages(SPECT) have relatively poor resolution. In an attempt to improve SPECT image quality, many methods have been developed for including anatomic information, extracted from higher resolution, structurally correlated Magnetic Resonance images(MRI), into SPECT reconstruction process. These methods provide improved SPECT reconstruction accuracy if the anatomic information is perfectly correlated with the SPECT functional information. However there exist mismatches between MRI anatomical structures and SPECT functional structures due to diierent imaging mechanisms. It has been reported that if the MR structures are applied into SPECT, the mismatched part will cause artifacts. This paper describes a joint estimation approach which uniies MR information extraction and SPECT reconstruction processes to avoid these artifacts. Both qualitative and quantitative evaluations show that the method improves the SPECT reconstruction where the MR information matches and is robust to mismatched MR information .