Ultraportable (UP) X-ray devices are ideal to use in community-based settings, particularly for chest X-ray (CXR) screening of tuberculosis (TB). Unfortunately, there is insufficient guidance on the radiation safety of these devices. This study aims to determine the radiation dose by UP X-ray devices to both the public and radiographers compared to international dose limits. Radiation dose measurements were performed with four UP X-ray devices that met international criteria, utilizing a clinically representative CXR set-up made with a thorax phantom. Scatter and leakage radiation dose were measured at various positions surrounding the phantom and X-ray tube, respectively. These measurements were used to calculate yearly radiation doses for different scenarios based on the median of all UP X-ray devices. From the yearly scatter doses, the minimum distances from the phantom needed to stay below the international public dose limit (1 mSv/year) were calculated. This distance was longest in the direction back towards the X-ray tube and shortest to the left/right sides of the phantom, e.g., 4.5 m and 2.5 m resp. when performing 50 exams/day, at 90 kV, 2.5 mAs and source skin distance (SSD) 1 m. Additional calculations including leakage radiation were conducted at a typical radiographer position (i.e., behind the X-ray tube), with a correction factor for wearing a lead apron. At 2 m behind the X-ray tube, a radiographer wearing a lead apron could perform 106 exams/day at 2.5 mAs and 29 exams/day at 10 mAs (90 kV, SSD 1 m), while keeping his/her radiation dose below the public dose limit (1 mSv/year) and well below the radiographer dose limit (20 mSv/year). In most CXR screening scenarios, the radiation dose of UP X-ray devices can be kept below 1 mSv/year by employing basic radiation safety rules on time, distance and shielding and using appropriate CXR exposure parameters.
Journal Article > ResearchFull Text
PLOS Glob Public Health. 24 January 2025; Volume 5 (Issue 1); e0003986.; DOI: 10.1371/journal.pgph.0003986
Paulis LE, Schnerr RS, Halton J, Qin ZZ, Chua A
PLOS Glob Public Health. 24 January 2025; Volume 5 (Issue 1); e0003986.; DOI: 10.1371/journal.pgph.0003986
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ArXiv.org e-Print archive. 14 June 2024; DOI:10.48550/arXiv.2406.10044
Paulis LE, Schnerr RS, Halton J, Qin ZZ, Chua AC
ArXiv.org e-Print archive
E-Print archive
ArXiv.org e-Print archive. 14 June 2024; DOI:10.48550/arXiv.2406.10044
Ultraportable X-ray devices are ideal for TB screening in resource limited settings. Unfortunately, guidelines on the radiation safety of these devices are lacking. The aim of this study was to determine the radiation dose by scattered and leakage radiation of four ultraportable X-ray devices to provide a basis for these guidelines. Radiation dose measurements were performed with four ultraportable X-ray devices that meet the WHO/IAEA criteria. An anthropomorphic thorax phantom was positioned in posterioranterior orientation in a clinically representative X-ray set-up. X-ray exams were acquired with the following scan parameters: 90 kV, 2.5 mAs and maximum mAs, 1 m and 1.8 m sourceskin-distance. The entrance skin dose was measured at the center of the phantom. The scattered radiation dose was measured at 1 m from the phantom as a function of scatter angle. Leakage radiation was measured at 0.5 m from the X-ray tube with collimators closed and covered with additional lead. From the scatter measurements the ‘safe distance bunny’ was determined, which was the minimum distance to the phantom to stay below the international dose limit to the public (1 mSv/year) at a given workload: longest distance (related to highest scatter dose) was observed behind the edges of the detector and back towards the X-ray tube, whereas shortest distance (related to lowest scatter dose) was observed to the sides of the phantom. For the radiographer position, the total radiation dose by scattered and leakage radiation was determined in various scenarios. In most cases, the total radiation dose of ultraportable X-ray devices can be kept below 1 mSv/year by employing basic radiation safety rules: 1. reduce time in the X-ray field, 2. increase distance to the X-ray source, and 3. use shielding measures (e.g. lead apron). Ultraportable X-ray devices can be safely used for TB screening when using adequate precautions.