Compensators for dose and scatter management in cone-beam computed tomography.
The ability of compensators (e.g., bow-tie filters) designed for kV cone-beam computed tomography (CT) to reduce both scatter reaching the detector and dose to the patient is investigated. Scattered x rays reaching the detector are widely recognized as one of the most significant challenges to cone-beam CT imaging performance. With cone-beam CT gaining popularity as a method of guiding treatments in radiation therapy, any methods that have the potential to reduce the dose to patients and/or improve image quality should be investigated. Simple compensators with a design that could realistically be implemented on a cone-beam CT imaging system have been constructed to determine the magnitude of reduction of scatter and/or dose for various cone-beam CT imaging conditions. Depending on the situation, the compensators were shown to reduce x-ray scatter at the detector and dose to the patient by more than a factor of 2. Further optimization of the compensators is a possibility to achieve greater reductions in both scatter and dose.
Graham
S A
SA
Ontario Cancer Institute, Princess Margaret Hospital, Department of Medical Biophysics, University of Toronto, Ontario, M5G 2M9, Canada.
Moseley
D J
DJ
Siewerdsen
J H
JH
Jaffray
D A
DA
D054893:Cone-Beam Computed Tomography; D006801:Humans; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D012542:Scattering, Radiation; D014965:X-Rays