The Fluoroscopic Image as Input Data for Computed Tomography

The use of a fluoroscopic imaging system for providing the projection data required in computerized tomography has been explored. The capability of both conventional systems and large flat screen-low light level vidio systems are discussed. The highlights of previously published data are also presented. Specific applications to radiation therapy are illustrated and the equipment described. The differential contrast senditivity is of the order of 0.5%, spatial resolution less than 0.5 mm, and slice thickness approximately 1 mm. Patient skin exposure is expected to be between 150 mR and 300 mR per scan.