[Use of patient radiation shielding in diagnostic and interventional radiology]. / Einsatz von Patienten-Strahlenschutzmitteln in der diagnostischen und interventionellen Radiologie.

The use of patient contact shielding provides an opportunity to reduce patient radiation exposure. Recently, the use has been the subject of controversy. The Radiation Protection Committee has published a recommendation on the use of patient radiation shields by considering the recent findings on dose savings but also the risks of incorrect use. In this article, a specification for the more frequently used types of X­ray examination is given, which describes whether and which radiation contact shielding should be used. This is accompanied by a rationale for the use or non-use of patient radiation protection agents. Problems and possible errors are explained, as well as how to deal with special situations such as pregnant women and children.

European consensus on patient contact shielding.

Patient contact shielding has been in use for many years in radiology departments in order to reduce the effects and risks of ionising radiation on certain organs. New technologies in projection imaging and CT scanning such as digital receptors and automatic exposure control (AEC) systems have reduced doses and improved image consistency. These changes and a greater understanding of both the benefits and the risks from the use of shielding have led to a review of shielding use in radiology. A number of professional bodies have already issued guidance in this regard. This paper represents the current consensus view of the main bodies involved in radiation safety and imaging in Europe: European Federation of Organisations for Medical Physics, European Federation of Radiographer Societies, European Society of Radiology, European Society of Paediatric Radiology, EuroSafe Imaging, European Radiation Dosimetry Group (EURADOS), and European Academy of DentoMaxilloFacial Radiology (EADMFR). It is based on the expert recommendations of the Gonad and Patient Shielding (GAPS) Group formed with the purpose of developing consensus in this area. The recommendations are intended to be clear and easy to use. They are intended as guidance, and they are developed using a multidisciplinary team approach. It is recognised that regulations, custom and practice vary widely on the use of patient shielding in Europe and it is hoped that these recommendations will inform a change management program that will benefit patients and staff.

A patient-centric approach to quality control and dosimetry in CT including CBCT.

One measurement and an algebraic formula are used to calculate the incident air kerma (Ka,i) at the skin after any CT examination, including cone-beam CT (CBCT) and multi-slice CT (MSCT). Empty scans were performed with X-ray CBCT systems (dental, C-arm and linac guidance scanners) as well as two MSCT scanners. The accumulated Ka,i at the flat panel (in CBCT) or the maximum incident air kerma at the isocentre (in MSCT) were measured using a solid-state probe. The average Ka,i(skin), at the skin of a hypothetical patient, was calculated using the proposed formula. Additional measurements of dose at the isocentre (DFOV) and kerma-area product (KAP), as well as Ka,i(skin) from thermoluminiscence dosimeters (TLDs) and size-specific dose estimates are presented for comparison. The Ka,i(skin) for the standard head size in the dental scanner, the C-arm (high dose head protocol) and the linac (head protocol) were respectively 3.33 ±â€¯0.19 mGy, 15.15 ±â€¯0.76 mGy and 3.23 ±â€¯0.16 mGy. For the first MSCT, the calculated Ka,i(skin) was 13.1 ±â€¯0.7 mGy and the TLDs provided a Ka,i(skin) between 10.3 ±â€¯1.1 mGy and 13.8 ±â€¯1.4 mGy. Estimation of patient air kerma in tomography with an uncertainty below 7% is thus feasible using an empty scan and conventional measurement tools. The provided equations and website can be applied to a standard size for the sake of quality control or to several sizes for the definition of diagnostic reference levels (DRLs). The obtained incident air kerma can be directly compared to the Ka,i from other X-ray modalities as recommended by ICRU and IAEA.