Comparison of a digital flat-panel versus screen-film, photofluorography and storage-phosphor systems by detection of simulated lung adenocarcinoma lesions using hard copy images.

The purpose of this study was to compare hard copy images from a flat-panel detector digital radiography system with conventional radiography, photofluorographic radiography and storage phosphor radiography for the detection of simulated lung adenocarcinoma lesions and also for radiation dose. To test the diagnostic performance of these four systems, the authors used 15 types of lung adenocarcinoma phantom according to Noguchi's classification and an anthropomorphic chest phantom. The visual evaluation of tumour detectability by four radiologists and two general thoracic surgeons was examined with a five-level confidence scale. Lung doses were measured with glass dosemeters for the chest radiology systems under the conditions used by each hospital and centre. Our results indicated that flat-panel detector digital radiography and storage phosphor radiography are not necessarily superior to conventional radiography and photofluorographic radiography for detecting lung adenocarcinomas when only hard copy images are used, and this suggests a need to carefully optimize chest radiography.

The quality assurance and constancy checking of fluoroscopy and fluorography systems.

X ray procedures which involve fluoroscopy often give significant radiation doses to patients. A valuable radiation protection procedure is the adoption of a quality assurance programme which will ensure the continual production of optimal quality images with the minimum necessary dose to the patient. Various publications exist which provide information on quality assurance (QA) and constancy checking of fluoroscopy and fluorography systems. These publications were reviewed and tests recommended for QA and constancy checking of fluoroscopy and fluorography systems are presented. It was found that not much information exists on QA and constancy checking for digital subtraction angiography and digital fluorography systems. More research is required in this field. Information on protocols used by various countries of the European Community for QA and constancy checking of fluoroscopy and fluorography systems was gathered. From this information it is apparent that there is a need for harmonisation within Europe.

Description and appraisal of a prototype digital fluorographic system.

A prototype system for digital fluorography (DF) has been developed from commercially available DSA equipment coupled to a standard screening unit. We present our initial clinical experience of this system with particular reference to the ergonomics, the image quality and the effect of image processing. We have concentrated upon dynamic studies such as upper gastrointestinal tract barium studies where the logistic advantages of the system are considerable. We have found DF to be ergonomically more efficient than conventional techniques. Using careful image processing the 512*512 matrix images were considered diagnostic for most studies assessed.

Multi-image camera for spot radiography at fluoroscopic examinations.

The image quality of photofluorographic spot films (70, 100 or 105mm) has bee gradually improving as high resolution image intensification has evolved. With newly available 1023-line fluoroscopic monitors providing 2.8 line pairs/mm resolution, it is now possible to photograph diagnostic images directly off the monitor. Such images provide detail similar to that currently available on 100mm spot films. A multi-image camera has been modified to record spot films from the video disc image resulting in marked reduction in patient radiation and film cost. Initial findings incorporating pulsed fluoroscopy using a video disc are discussed.

[Proceedings: 70 mm photofluorography: a valuable aid in coronary angiographic studies]. / 70-mm-Photofluorographie: eine wertvolle Hilfe bei koronarangiographischen Untersuchungen

With the development of new intensifiers using cesium iodide as the input phosphor and having a spatial frequency of up to 4 lines/mm, it has become possible to obtain high contrast serial photographs using a 70 mm camera. In 48 patients undergoing coronary arteriography, 35 mm cine and 70 mm spotfilms were obtained at exposures as follows: 3 msec, 75-95 kV at 200 mA for the 35 mm cine (50 frames/sec) and 6-10 msec, 75-95 kV at 300 mA (4 FRAMES/SEc) for the 70 mm images. Image quality and diagnostic information of the two media were compared. 70 mm films were of excellent quality. The vessel edges showed up sharp, the pictures were high in contrast, and small arteries in particular could be well defined. 70 mm photofluorography offers many advantages which are discussed.