The influence of different technique factors on image quality of chest radiographs as evaluated by modified CEC image quality criteria

Abstract

The Commission of the European Communities (CEC) research project "Predictivity and optimisation in medical radiation protection" addressed fundamental operational limitations in existing radiation protection mechanisms. The first part of the project aimed at investigating (1) whether the CEC image quality criteria could be used for optimization of a radiographic process and (2) whether significant differences in image quality based on these criteria could be detected in a controlled project with well known physical and technical parameters. In the present study, chest radiographs on film were produced using healthy volunteers. Four physical/technical parameters were varied in a carefully controlled manner: tube voltage (102 kVp and 141 kVp), nominal speed class (160 and 320), maximum film density (1.3 and 1.8) and method of scatter reduction (grid (R=12) and air gap). The air kerma at the entrance surface was measured for all patients and the risk-related dose H(Golem), based on calculated organ-equivalent dose conversion coefficients and the measured entrance air kerma values, was calculated. Image quality was evaluated by a group of European expert radiologists using a modified version of the CEC quality criteria. For the two density levels, density level 1.8 was significantly better than 1.3 but at the cost of a higher patient radiation exposure. The correlation between the number of fulfilled quality criteria and H(Golem) was generally poor. An air gap technique resulted in lower doses than scatter reduction with a grid but provided comparable image quality. The criteria can be used to highlight optimum radiographic technique in terms of image quality and patient dose, although not unambiguously. A recommendation for good radiographic technique based on a compromise between image quality and risk-related radiation dose to the patient is to use 141 kVp, an air gap, a screen-film system with speed 320 and an optical density of 1.8.

Correlation of the clinical and physical image quality in chest radiography for average adults with a computed radiography imaging system

“…The monitors were calibrated to national standards [27]. Image criteria were based on the Council of European Communities (CEC) Quality Criteria [28], slightly revised to reflect modern diagnostic requirements and experiences of other groups [29][30][31][32][33]. Test images (50, 60, 70, 81, 90, 109, 125, 133, 141 and 150 kV) were scored against a reference image at a tube voltage of 102 kV, with negative and positive scores indicating inferior and superior image quality, respectively (tube voltages stated here were those available on the Philips radiographic system).…”

Use of a digitally reconstructed radiograph-based computer simulation for the optimisation of chest radiographic techniques for computed radiography imaging systems

“…The image criteria described in the CEC document, slightly revised [38][39][40][41][42] to reflect modern diagnostic requirements and previous experiences of other groups, were used to define anatomical features in each chest image for evaluation. As well as general chest structures, lung abnormalities were simulated in each image and evaluated, and are shown in Table 2.…”

New Developed DR Detector Performs Radiographs of Hand, Pelvic and Premature Chest Anatomies at a Lower Radiation Dose and/or a Higher Image Quality

“…A total of 450 test images were scored in accordance with the VGA scale from −2 to +2 as shown in Table 3 [27][28][29].…”

“…In order to reduce bias in the VGA scores the radiologists were given 'unlimited' time and allowed to work undisturbed. The VGA experiment was undertaken at the same physical location with the same PACS system, diagnostic monitor and physical surroundings 23,27]. To examine intra-observer agreements 10 % of the 450 anthropomorphic images were repeatedly presented to the radiologists in the VGA experiments.…”