Low-dose CT in SPECT/CT patient scan

Advanced single-photon emission computed tomography (SPECT) includes a cone-beam computed tomography (CBCT) unit for acquisition of anatomic information about the imaged subject. CT images obtained can be used for attenuation correction in SPECT and localization determination. Hardware considerations have led to the use of an imaging configuration in which the CBCT field of view (FOV) is extended through the use of an offset detector. In general, current clinical CBCT applications involve data acquired at a large number of views. Therefore, the accumulated radiation dose integrated over a large number of views can be of a health concern. In this work, we report our preliminary investigation of image reconstruction by using the recently developed adaptive steepest descent-projection onto convex sets (ASD-POCS) algorithm from real patient data collected at a number of views much fewer than what are used currently in CBCT imaging in clinical SPECT/CT studies.