| 摘要 |
The present invention is, in one embodiment, a method for determining tracking control parameters for positioning an x-ray beam (16) of a computed tomography imaging system (10) having a movable collimator (52) positionable in steps and a detector array (20) including a plurality of rows (54, 56, 58, 60) of detector elements. The method includes steps of obtaining detector samples at a series of collimator step positions while determining a position of a focal spot of the xray beam (16); determining a beam position for each detector element at each collimator step utilizing the determined focal spot positions, a nominal focal spot length, and geometric parameters of the x-ray beam (16), collimator (52) , and detector array; and determining a calibration parameter utilizing information so obtained. For example, in determining a target beam position at which to maintain the x-ray beam (16), a detector element differential error is determined according to ratios of successive collimator step positions; and a target beam position is selected for an isocenter element in accordance with the determined element differential errors. <IMAGE> <IMAGE> |
