Method and apparatus to obtain limited angle tomographic images from stationary gamma cameras
A nuclear imaging system and method for performing three-dimensional imaging of anatomical structures. The system and method includes two or more gamma ray detectors each used in combination with a variable-slant hole collimator. The detectors are positioned in close proximity to, or in contact with, the structure being imaged. The detectors remain in a stationary position during the data collection process. An imaging or reconstruction method is then used to reconstruct a three-dimensional image from the data derived from the detectors.
1. A method of imaging an anatomical structure comprising the steps of: administering a gamma radiation emitting radiopharmaceutical such that at least a portion of said radiopharmaceutical accumulates in an anatomical structure being imaged; positioning at least two gamma ray detectors, each incorporating a variable-angle slant hole collimator, such that each detector has the structure in its respective field of view; defining one or more acceptance angles for each gamma ray detector; acquiring projection image data from the structure over a continuous angular range of the acceptance angle of each gamma ray detector; and, generating a gamma ray image of the anatomical structure by evaluating and considering the data derived from the imaging method, said data comprising the location of the detectors, the field of view of the detectors, the response of the detectors to gamma rays originating within the acceptance angle of the collimator and the response of the detectors to gamma rays originating within the field of view but outside the acceptance angle of the collimators.
2. The method of claim 1 wherein generating a gamma ray image further comprises iteratively processing said data to obtain limited angle SPECT images of the accumulated radiopharmaceuticals in said structure.