title: A study on image quality provided by a kilovoltage cone-beam computed tomography.
abstract: The image-guided radiotherapy technique (IGRT) makes use of imaging devices to verify the positions of the target volume and organs at risk during the treatment sessions. In this work we evaluate the image quality provided by an imaging system based on a kilovoltage cone-beam CT, and explore its ability to perform IGRT and adaptive radiotherapy. We analyze the accuracy of the image slice width, the spatial resolution using the MTF function, the image uniformity, the signal-to-noise ratio, the contrast-to-noise ratio, the low-contrast sensitivity, and the HU linearity with density. The studied parameters are evaluated in an objective and quantitative way, allowing for a direct comparison with other imaging devices. We conclude that the analyzed cone-beam imaging system is adequate to accurately perform IGRT within its clinical use, despite the high level of noise present in a cone beam caused by scatter. We also point out the presence of a bowtie wobble artifact in the reconstructed images. Nevertheless, we conclude that these features do not limit the capability of the system to perform adaptive radiotherapy in most cases.
authors: Servicio de Radiofísica, Hospital Universitario Puerta de Hierro – Majadahonda, Majadahonda, Madrid, Spain.garayoa.julia@gmail.com
authors: Julia
authors: J
authors: Garayoa
authors: Pablo
authors: P
authors: Castro
mesh_terms: D000465:Algorithms; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity