Article 1 Bremsstrahlung imaging 1 Kernel method 1 SPECT-CT 1 Synergistic image reconstruction 1 Tomographic image reconstruction 1 brems radiation clinical article 1 contrast to noise ratio 1 controlled study 1 human 1 image reconstruction 1 mathematical model 1 radioembolization 1 selective internal radiation therapy 1 single photon emission computed tomography 1 single photon emission computed tomography-computed tomography 1 yttrium 90 1