Physical aspects of photostimulable phosphor computed radiography

Abstract

Currently photostimulable phosphor computed radiography (PPCR) promises to be the digital X-ray image acquisition technology of choice for classical radiography (i.e. X-ray examinations of natural anatomy). For the last two years we have been carrying out a physical evaluation of modern PPCR technology and some of our findings relevant to general radiographic applications are reviewed here. Topics covered include the function of the auto-reader system and the reliability of image reproduction, the radiation exposure requirement and physical image quality. The latter is based upon both objective and subjective measures of image quality. These studies have yielded a favourable comparison of the image quality of modern PPCR technology with that of medium-speed and fast radiographic screen-film combinations. The major advantages of PPCR appear to be the maintenance of high imaging efficiency (DQE) over a much wider range of signal levels than film and consistent image acquisition and presentation independent of exposure level. In general radiographic applications no major limitations due to the comparatively modest limiting spatial resolution of PPCR [maximum limiting resolution = 5 line-pair mm-1] have been experienced. Digital image enhancement is a central element of PPCR image reproduction. The authors believe that advances in image enhancement algorithms remain a potential area for further improving the presented quality of PPCR images.

Effects of Varying Filter Kernel Sizes on the Image Quality of Interstitial Lung Diseases

“…The evaluation of Xrayed storage phosphor plates (type ST-I) was performed using Digiscan 901 (Siemens). The digital image processing in luminescence radiography and the basics of image postprocessing have been de-' scribed previously (1,5,11,14,16,25).…”

Comparison of computed radiography and film/screen combination using a contrast‐detail phantom

“…It is shown that the CR systems may have improved low contrast resolution 11 Threshold contrast detail detectability has been the test to assess such image quality of digital radiographic systems 12 . The contrast‐detail detectability depends upon various factors such as the noise, radiation exposure level, spatial resolution, contrast resolution, visual response of the observer, etc.…”

Cephalogram pseudo-color and emboss enhancements : anatomical landmark clarity in photostimuable phosphor cephalometrics.

“…Disadvantages encountered are mostly attributed to the system's automated image acquisition process including an occasional inability to handle collimated images and difficulty for the user to interpret exposure levels recorded on the images. 4 Cowen stressed steps being taken by equipment suppliers and manufacturers to resolve these problems. 4 In contrast to film, photostimuable phosphor (PSP) systems are said to present several advantages supporting their use in digital radiography.…”

“…4 Cowen stressed steps being taken by equipment suppliers and manufacturers to resolve these problems. 4 In contrast to film, photostimuable phosphor (PSP) systems are said to present several advantages supporting their use in digital radiography. These consist of highly reliable image reproduction, ease of data storage and retrieval, lack of need for chemical processing, and possible x-ray exposure reduction to patients.…”

“…Cowen collected that due to its wide dynamic range, the storage phosphor system's noise source depends on the signal level within a specific range 4 . At low exposure quantum noise may be the main source, while at high exposure structure mottle and reader noise are of main concern.…”