Image Acquisition and Attenuation Map Estimation for Multi-pinhole Clinical SPECT

Single-photon emission computed tomography (SPECT) is a well-established nuclear imaging modality for studying functional and pathological properties of the brain. Conventional general purpose SPECT systems typically offer a spatial resolution of about 10 mm with a sensitivity of 0.01-0.02%. A few dedicated brain SPECT scanners have been proposed, but resolutions and sensitivities are no better than 7 mm and 0.03% respectively, and some of these scanners are not manufactured anymore. This limited resolution hampers detection of localized brain abnormalities, while the low sensitivity requires a long scanning time that limits fast dynamic studies. Besides a compromised resolution and sensitivity, conventional SPECT systems require rotation of heavy detectors to obtain sufficient angular projections, which hamper fast dynamic imaging.