A New Image Reconstruction Technique with Limited View-angle Projection Data for BNCT-SPECT

This study proposed a novel image reconstruction technique using Bayesian estimation for Single-Photon Emission Computed Tomography (SPECT) in Boron Neutron Capture Therapy (BNCT) with limited view-angle projection data, and compered the performance with the existing method, ML-EM. BNCT requires real-time visualization of therapeutic effects, that is, output of reconstructed images to show local boron dose. Since BNCT-SPECT is a treatment, not a diagnosis, there are limits related to projection angle and measuring time. It should be noted that in BNCT-SPECT, unlike normal image reconstruction like Xray CT, the accuracy of each pixel value (dose) is more important than the structural similarity to the true image. This is because the most crucial estimate value is the patient's exposure dose in the normal cells. Therefore, we devised a method using Bayesian estimation as an image reconstruction method that could reproduce an individual pixel value accurately. As a result of numerical simulation, it was found that the proposed method is superior to the ML-EM method in terms of Mean Absolute Error (MAE). As the next step, we are planning to evaluate the performance of the proposed method using the measurement data acquired in the experiment.