Abstract
Understanding how contrast is produced and controlled in computed tomography (CT) is essential to proper application of this modality. In the typical CT scanner, a narrow x-ray beam in the section thickness direction and an air gap in the section plane are used to reduce scatter and improve contrast. High- and low-contrast detectability of a CT scanner are important performance parameters contributing to optimal image quality. The limits of detectability of high-contrast objects (ie, spatial resolution) are affected by detector aperture size, pixel size of the image, algorithm used to reconstruct the image, and section thickness. Visibility of low-contrast objects is limited by image noise and the algorithm. Contrast in CT images can be controlled by the window level and window width settings used to display the image. These settings dictate how the actual measurements of tissue attenuation are translated into a gray-scale image. Wide window widths can be used to provide an accurate representation of bone, and narrow widths are more useful for visualizing soft tissues.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.