Single Photon Emission Computed Tomography with Increased Sampling Density at Central Region of Field-of-View

Single photon emission computed tomography (SPECT) systems are proposed which provide images with improved signal-to-noise ratio. The systems consist of gamma cameras equipped with collimators which view an object to be imaged with an increased sampling density in the vicinity of the center of a field-of-view. The detection systems produce weighted projection data. Evaluation was made with respect to noise characteristics in images resulting from such systems. Simulation studies showed that dual and quadruple camera systems equipped with a combination of fan beam collimators result in noise reduction of about 37% at the center of image and uniform noise over an image area, compared with systems equipped with parallel hole collimators. This suggests that the proposed systems have a possibility of improvement on quantitation of SPECT.