| 摘要 |
<p>A CT therapy scanner moves a therapy X-ray source in an arc about a subject. A tumor or lesion is isocentered by the X-ray beam which is a pencil beam. A fan beam (13), from which the pencil beam (16) is obtained, provides for visualization thereby to ensure that X-ray therapy is accurately delivered. A collimator (15) provides for the conversion of a fan beam to a pencil-fan beam characteristic.</p> |
