Numerical results for iterative image reconstruction in half-scan and non-uniform attenuated SPECT

The quality of reconstructed image in Single-Photon Emission Computed Tomography (SPECT) is strongly degraded by the photon attenuation. In general, the attenuation correction on SPECT images requires the data to be known over 2π (full-scan). The reduction of data acquisition from 2π to π (half-scan) in SPECT is recommended because it reduces the scanning time; thereby, minimizing the patient’s motion and making the exam less uncomfortable for the patient. Algorithms and numerical research has been developed on image reconstruction from data acquired over π in SPECT with non-uniform attenuation. However, it remains theoretically unknown whether data, acquired only over π in SPECT with nonuniform attenuation, contain complete information for accurate image reconstruction. In this work, we present numerical results on image reconstruction in halfscan SPECT with non-uniform attenuation. The numerical simulations are based on a new iterative reconstruction algorithm that introduces exact and implicit attenuation correction. Specifically, we show that the algorithm is able to reconstruct images, in half-scan SPECT, with quality very similar to those reconstructed in full-scan SPECT. Moreover, the numerical simulations show that the algorithm is stable and convergent.