Abstract: A computed tomography apparatus is provided that includes a single photon emission computed tomography (SPECT) multi-pinhole collimator, where the multi-pinhole collimator includes an aperture plate and a grid pattern of pinholes disposed in the aperture plate, and the pinholes include through-holes each having a central axis pointing at a common focal point at a finite distance from the aperture plate. The multi-pinhole collimator is disposed for radionuclide imaging using nuclear medicine therapies that include TI-201, Tc-99m, I-123, In-111 or I-131. Here, the radionuclide imaging can include brain radionuclide imaging, cardiac radionuclide imaging, bladder radionuclide imaging, thyroid radionuclide imaging, breast radionuclide imaging, prostate gland radionuclide imaging, or adrenal gland radionuclide imaging. The grid pattern includes up to 5 pinholes across the aperture plate and up to 4 pinholes down the aperture plate.