Detection of subtle microcalcifications: comparison of computed radiography and screen-film mammography.

Abstract

Observer performance tests were conducted to compare the effects of image-processing technique (unsharp mask filtering) on the diagnostic accuracy of computed radiography (CR) with storage phosphors in the detection of microcalcifications. Comparison of detectability of microcalcifications with CR and with screen-film mammography was also performed. Clusters of microcalcifications (125-250 microns in diameter) were randomly superimposed on human breast specimens. Observer performance tests were carried out with receiver operating characteristic (ROC) analysis. The area under the ROC curve and the cumulative true-positive-localization fraction were both used as indexes of performance. Observer performance experiments with nine observers indicated that the two types of screen-film images used provided higher detectability than the CR images. The detectability of microcalcifications on the CR images improved slightly with use of the unsharp masking technique. However, no statistically significant difference was found between processed and unprocessed CR images, and detectability still did not reach the level achieved with the screen-film images.

Storage phosphor and film-screen mammography: performance with different mammographic techniques

“…Some studies have not shown significant differences between computed tomography and conventional technique [2,3,5,7], whereas others have shown better results for the conventional technique [5,9]. Even if some results did not indicate any differences, artefacts on the digital mammograms were sometimes misjudged as microcalcifications [2].…”

“…Several studies of digital mammography [2±7] have shown no significant differences between digital and screen-film techniques. Some studies [8,9], however, have reported inferior results for the digital technique compared with the screen-film technique.…”

“…Several studies of digital mammography [2±7] have shown no significant differences between digital and screen-film techniques. Some studies [8,9], however, have reported inferior results for the digital technique compared with the screen-film technique.Since digital mammography is still the object of discussion, it was decided to evaluate the image quality of digital mammograms by comparing the image quality of storage phosphor plates and screen-film mammograms, using an anthropomorphic breast phantom and simulated pathology in a modified free-response receiver operating characteristics (FROC) detection experiment. Two mammographic units were studied.…”

Perception of anatomical structures in digitally filtered and conventional panoramic radiographs: a clinical evaluation

“…The technique is frequently used in medical radiology to evaluate diagnostic image quality and provides two radiographs simultaneously with a single exposure. 11,12 It has been proved that the technique offers single-exposure imaging with only nominal degradation in film and SPP image quality, relative to the two standard image counterparts and, therefore, has been adopted as the method of choice in the present study to avoid the added radiation exposure to patients. 13,14 After exposure, films were processed in an automatic processor (XR 24; Dü rr, Bietigheim, Germany) while phosphor plates were read on a Digora PCT laser scanner.…”

Interobserver agreement and performance score comparison in quality control using a breast phantom: screen-film mammography vs computed radiography

“…As for image quality, the accuracy of CR reading is affected by the image-processing parameters and windowing [7,8,9]. Kallergi et al [10] reported that interobserver variation in the digitized mammogram reading (105-µm pitch, 12-bit gray scale) was greater than in the film reading.…”