Investigation of grid performance using simple image quality tests.

Antiscatter grids improve the X-ray image contrast at a cost of patient radiation doses. The choice of appropriate grid or its removal requires a good knowledge of grid characteristics, especially for pediatric digital imaging. The aim of this work is to understand the relation between grid performance parameters and some numerical image quality metrics for digital radiological examinations.

Performance tests for mammographic film-screen combinations: use of absolute techniques.

Purpose: A performance comparison of film-screen combination used in mammography was conducted using conventional and new techniques.

Materials And Methods: The performance of 30 mammographic film-screen combinations was evaluated by sensitometry, and the total performance was determined using phantom measurements. Quantum detection and light emission efficiency of the screens were also measured as an alternative technique for determining screen speeds.

Accuracy of clinical protocols in SPECT.

Unlabelled: The accuracy of clinical SPECT is highly dependent on the acquisition and processing parameters, which are selected according to the clinical task. These parameters are usually set within protocols in order to allow for standardization from one study to another and to speed up the clinical routine.

Methods: In the first part of this work, tomographic images of a Jaszczak phantom were obtained on 5 different SPECT systems using 2 common clinical protocols and each system's default acquisition and processing parameters.

Radiation exposure to premature infants in a neonatal intensive care unit in Turkey.

Objective: The aim of this work was to determine the radiation dose received by infants from radiographic exposure and the contribution from scatter radiation due to radiographic exposure of other infants in the same room.

Materials And Methods: We retrospectively evaluated the entrance skin doses (ESDs) and effective doses of 23 infants with a gestational age as low as 28 weeks. ESDs were determined from tube output measurements (ESD(TO)) (n = 23) and from the use of thermoluminescent dosimetry (ESD(TLD)) (n = 16).

Variations in breast doses for an automatic mammography unit.

Purpose: To assess variations of glandular doses for a group of patients when different dose modes are selected for a specific system.

Materials And Methods: All measurements were obtained with a Senographe DMR mammography unit (GE Medical Systems). Automatic exposure control with either contrast or standard mode was routinely used in patient examinations.

Performance measurements of mammographic systems.

Performance measurements of 30 mammographic installations were carried out in order to see the current level of image quality and breast doses.The half of the systems tested in this survey indicated automatic exposure control and beam collimation problems. Film processing and dark room conditions were not optimum for the majority of the installations.

Patient doses and dosimetric evaluations in interventional cardiology.

Interventional cardiological examinations may be associated with excessive radiation exposures which may cause skin injuries and higher probabilities of stochastic effects. Dose-area product (DAP) and skin doses of 325 patients were measured using alternative dosimetric techniques for different cardiological examinations. Data were collected from five different systems with the involvement of 11 cardiologists.

Investigation of mean glandular dose versus compressed breast thickness relationship for mammography.

The relationship between the mean glandular dose (MGD) and the compressed breast thickness (CBT) is commonly used for the presentation of mammographic dose survey results and could also be useful for the assessment of individual breast doses retrospectively in case of lack of necessary dosimetric instrumentation. The high data scattering from the best fit reduces the reliability of this technique. The aim of this study was to investigate the accuracy of this relationship using the data collected from a patient survey and phantom experiment.

Effects of radiologists' skill and experience on patient doses in interventional examinations.

In this study, effects of radiologists' skill and experience on patient doses were investigated. Dose-area product and entrance surface doses of two groups of patients, one examined by a number of junior radiologists and another one by a senior radiologist, have been compared for the diagnostic interventional examinations of cerebral and lower limbs. Collimation of the X-ray beam and shortening the fluoroscopy times by the senior radiologist considerably reduced the patient doses for interventional cerebral examinations.

Variations of patient doses in interventional examinations at different angiographic units.

Purpose: We analyzed doses for various angiographic procedures using different X-ray systems in order to assess dose variations.

Methods: Dose-area product (DAP), skin doses from thermoluminescent dosimeters and air kerma measurements of 308 patients (239 diagnostic and 69 interventional) were assessed for five different angiographic units. All fluoroscopic and radiographic exposure parameters were recorded online for single and multiprojection studies.