Megavoltage cone-beam computed tomography using a high-efficiency image receptor.

Purpose: To develop an image receptor capable of forming high-quality megavoltage CT images using modest radiation doses.

Methods And Materials: A flat-panel imaging system consisting of a conventional flat-panel sensor attached to a thick CsI scintillator has been fabricated. The scintillator consists of individual CsI crystals 8 mm thick by 0.