Phantom and method for accuracy and repeatability testing of positional mechanisms of computer assisted tomography and magnetic resonance imaging systems

摘要

A transparent measuring phantom apparatus and method facilitates rapid testing of the accuracy and repeatability of the scan position mechanisms of patient support table movements of computer assisted tomography (CAT) and magnetic resonance imaging (MRI) systems. The phantom includes clear transparent acrylic sections and radiopaque acrylic numerals which are all adhesively or solvent bonded into the phantom. The phantom includes an acrylic tube enclosing a base plate, a longitudinally extending slice location bar, a plurality of sequential position indicator numerals and operator position indicator numerals between a pair of end plates. The slice locator bar has an array of slice locator holes. In operation, the long axis of the phantom is aligned with the long axis of table movement that determines the slice location. The slice locator holes are drilled into the slice locator bar in a repeating pattern. Each line of holes includes a deep center hole and a plurality of grade marker holes of lessor depth on each side of the center hole. The grade marker holes are placed on an angle of about 70.5 degrees from the horizontal. An X-ray beam or MRI scan scans through the phantom at any desired location to determine the accuracy of the movement mechanisms of the patent support table relative to the plane of the X-ray beam or MRI scan.