Image enhancement and processing for positron emission tomography

A filtering method for positron emission tomography is proposed. The image is converted from the rectangular x-y coordinate system to the polar ρ-θ coordinate system. This causes the radial noise to map into horizontal lines. Using the Fourier transform, radial noise is then mapped into and around the vertical axis of the Fourier spectrum in the corresponding ω-θ space. A class of filters is designed and applied to these images. The filtered images are then converted back to a rectangular coordinate system for display and examination. This method has been tested using both synthetic and real data. The corrected images show minor residual noise and practically no loss of information around the heart wall