AAPM/RSNA Physics Tutorial for Residents: Physics of Flat-Panel Fluoroscopy Systems

Survey of Modern Fluoroscopy Imaging: Flat-Panel Detectors versus Image Intensifiers and More
Published Online:https://doi.org/10.1148/rg.312105185

In fluoroscopy imaging systems, flat-panel detectors (FPDs) are replacing image intensifiers as the modern solid-state image receptors; FPDs have potential to reduce patient radiation doses and to eliminate image degradation due to glare, vignetting, spatial distortions, and defocusing effects.

This article reviews the design and operation of both flat-panel detector (FPD) and image intensifier fluoroscopy systems. The different components of each imaging chain and their functions are explained and compared. FPD systems have multiple advantages such as a smaller size, extended dynamic range, no spatial distortion, and greater stability. However, FPD systems typically have the same spatial resolution for all fields of view (FOVs) and are prone to ghosting. Image intensifier systems have better spatial resolution with the use of smaller FOVs (magnification modes) and tend to be less expensive. However, the spatial resolution of image intensifier systems is limited by the television system to which they are coupled. Moreover, image intensifier systems are degraded by glare, vignetting, spatial distortions, and defocusing effects. FPD systems do not have these problems. Some recent innovations to fluoroscopy systems include automated filtration, pulsed fluoroscopy, automatic positioning, dose-area product meters, and improved automatic dose rate control programs. Operator-selectable features may affect both the patient radiation dose and image quality; these selectable features include dose level setting, the FOV employed, fluoroscopic pulse rates, geometric factors, display software settings, and methods to reduce the imaging time.

© RSNA, 2011


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Article History

Received: Aug 25 2010
Revision requested: Sept 17 2010
Revision received: Oct 11 2010
Accepted: Oct 19 2010
Published online: Mar 7 2011
Published in print: Mar 2011