A preliminary investigation of CT-dose reduction in SPECT/CBCT

In single-photon emission computed tomography (SPECT) imaging, the attenuation map can be estimated from cone-beam computed tomography (CBCT) images for attenuation correction. However, radiation dose involved in CBCT scans constitutes a potential health concern to the imaged subject. An approach to reducing CBCT-imaging dose is to decrease the number of views at which projections are acquired. Analytic-based algorithms may not be suitable for this type of data because they generally require data collected at a large number of densely distributed views. On the other hand, optimization-based reconstruction algorithms based on a discrete linear model have been demonstrated to be capable of reconstructing accurate images from projections fewer than those required by analytic-based algorithms. In the work, we investigate low-dose CT imaging in SPECT/CBCT attenuation correction by lowering number of projection views. The results demonstrated that CT-imaging dose in SPECT/CBCT may be reduced significantly by use of optimization-based reconstruction algorithms.