论文信息 - Comparison of low-contrast detail detectability with five different conventional and digital radiographic imaging systems

Comparison of low-contrast detail detectability with five different conventional and digital radiographic imaging systems

Five different X-ray imaging systems were evaluated comparatively with respect to low-contrast detail deductibility. The systems included in this study were two screen-film systems (speed classes 200 and 400), a computed radiography system, a digital selenium-based system with electrometer scanning and an indirect-type flat-panel detector system. Images of a contrast-detail phantom were acquired with all systems at a set of exactly matched exposures. The digital images were processed in a way to approximate the density and contrast appearance of the conventional film images when printed on laser film. Six observers evaluated a total number of 46 films. With respect to the threshold contrast for each detail size. Correct observation ratios and threshold contrasts were determined for all sizes and conditions. The overall results show that the low-contrast deductibility with all digital imaging systems is equal to or better than that with the conventional film-screen systems. The advantage is more evident for the newer digital systems (selenium detector and flat-panel detector) whereas the CR images are more on a par with the conventional films. The results can be understood assuming that low-contrast detection is limited mainly by quantum noise in the images and taking into account the different levels of detective quantum efficiency of these imaging systems.

[1] A R Cowen,et al. A comparison of the physical imaging properties of Fuji ST-V, ST-VA, and ST-VN computed radiography image plates. , 1998, Medical physics.

[2] G G Cox,et al. Comparison of the low-contrast detectability of a screen-film system and third generation computed radiography. , 1994, Medical physics.

[3] Thierry Ducourant,et al. New CsI/a-Si 17" x 17" x-ray flat-panel detector provides superior detectivity and immediate direct digital output for general radiography systems , 1998, Medical Imaging.

[4] J A Rowlands,et al. X-ray detectors for digital radiography. , 1997, Physics in medicine and biology.

[5] R. Aufrichtig,et al. Comparison of low contrast detectability between a digital amorphous silicon and a screen-film based imaging system for thoracic radiography. , 1999, Medical physics.

[6] C E Ravin,et al. Threshold perception performance with computed and screen-film radiography: implications for chest radiography. , 1992, Radiology.

[7] U Neitzel,et al. Image quality of a digital chest radiography system based on a selenium detector. , 1994, Medical physics.

[8] A R Cowen,et al. A comprehensive physical image quality evaluation of a selenium based digital x-ray imaging system for thorax radiography. , 1998, Medical physics.

[9] K Faulkner,et al. The contrast-detail behaviour of a photostimulable phosphor based computed radiography system. , 1994, Physics in medicine and biology.