Threshold contrast detail detectability curves for fluoroscopy and digital acquisition using modern image intensifier systems.

Threshold contrast detail detectability (TCDD) test objects are a commonly used tool to assess image quality of imaging systems. FAXIL (The Facility for the Assessment of X-ray imaging, Leeds) produced updated standard TCDD curves, for fluoroscopy systems in good adjustment, in 1992. Fluoroscopy curves can be corrected to account for the effect of image intensifier input air kerma rate and field size. This paper presents updated TCDD curves for fluoroscopy and new curves for digital acquisition. The results for digital acquisition suggest that the TCDD curves should not be corrected for input air kerma, as the quantum noise is not dominant and system noise is significant. These curves will prove useful for accepting new equipment, to give an indication of the expected image quality for a new image intensifier system.