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Purpose: To determine the influence of optimal collimation during lumbar spine radiography on radiation dose and image quality., Material and Methods: 110 lumbar spine patients were split into two groups-the first imaged with standard collimation and the second with optimal collimation. Body mass index, image field size, exposure conditions and dose area product were measured. Effective and absorbed organ doses were calculated. Image quality was assessed., Results: Optimal collimation reduced the primary field by up to 40%. The effective dose was reduced by 48% for the AP projection, while no differences were found for the LAT projection due to incorrect positioning of the central beam with standard collimation. The absorbed dose to selected radiosensitive organs decreased by 41 and 10% in the AP and LAT projections, respectively. Image quality for the LAT projection improved by 24% and maintained for the AP projection., Conclusion: Optimal collimation in lumbar spine imaging significantly influences patient exposure to radiation., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Interventional cardiac procedures not only lead to significant effective doses for the patient but also can potentially cause deterministic effects on the patient's skin. Information about the peak (maximal) skin doses (PSD) received by patients during percutaneous transluminal coronary angioplasty procedures were collected from three cardiac catheter rooms. Cumulative dose at the interventional reference point (CD(IRP)) was collected for 161 patients and for 16 patients PSD was determined using Gafchromic dosimetry films. The comparison showed that CD(IRP) readings give a useful but conservative estimation of patient peak skin dose as it can lead to a significant overestimation. The median and third quartile values of CD(IRP) were 0.64 and 0.92 Gy, respectively. The 2 Gy threshold for deterministic effects was exceeded in nine patients. A good correlation was found between CD(IRP) and kerma area product measurements while the correlation with fluorography time was very weak.

In Slovenia, dental radiography was the first field in which projection x-ray imaging using digital detectors was done. At present around 30% of intraoral dental x-ray units use digital detectors. Annual test results were analysed to compare digital systems with film-based ones. The survey results show significantly lower doses of exposure in digital systems. In our opinion digital systems are especially suitable for practitioners who perform a low number of x-ray examinations (e.g. private dentists), because of problems that may arise due to developing a limited number of films. The problem with digital systems could be the ease of deleting an image and performing another examination, the extent of which was not investigated.