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- Båth, Magnus, 1974, et al.
(författare)
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Effective dose to patients from chest examinations with tomosynthesis
- 2010
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 139:1-3, s. 153-158
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Tidskriftsartikel (refereegranskat)abstract
- Chest tomosynthesis, which refers to the principle of collecting low-dose projections of the chest at different angles and using these projections to reconstruct section images of the chest, is an imaging technique recently introduced to health care. The main purpose of the present work was to determine the average effective dose to patients from clinical use of chest tomosynthesis. Exposure data for two chest radiography laboratories with tomosynthesis option (Definium 8000 with VolumeRAD option, GE Healthcare, Chalfont St. Giles, UK) were registered for 20 patients with a weight between 60 and 80 kg (average weight of 70.2 kg). The recorded data were used in the Monte Carlo program PCXMC 2.0 (STUK-Radiation and Nuclear Safety Authority, Helsinki, Finland) to determine the average effective dose for each projection. The effective dose for the chest tomosynthesis examination, including a scout view and the tomosynthesis acquisition, was finally obtained by adding the effective doses from all projections. Using the weighting factors given in ICRP 103, the average effective dose for the examination was found to be 0.13 mSv, whereas the average effective dose for the conventional two-view chest radiography examination was 0.05 mSv. A conversion factor of 0.26 mSv Gy(-1) cm(-2) was found suitable for determining the effective dose from a VolumeRAD chest tomosynthesis examination from the total registered kerma-area product. In conclusion, the effective dose to a standard-sized patient (170 cm/70 kg) from a VolumeRAD chest tomosynthesis examination is ~2 % of an average chest CT and only two to three times the effective dose from the conventional two-view chest radiography examination.
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- Magee, Jill S, et al.
(författare)
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Derivation and application of dose reduction factors for protective eyewear worn in interventional radiology and cardiology.
- 2014
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Ingår i: Journal of radiological protection : official journal of the Society for Radiological Protection. - : IOP Publishing. - 1361-6498. ; 34:4, s. 811-823
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Tidskriftsartikel (refereegranskat)abstract
- Doses to the eyes of interventional radiologists and cardiologists could exceed the annual limit of 20mSv proposed by the International Commission on Radiological Protection. Lead glasses of various designs are available to provide protection, but standard eye dosemeters will not take account of the protection they provide. The aim of this study has been to derive dose reduction factors (DRFs) equal to the ratio of the dose with no eyewear, divided by that when lead glasses are worn. Thirty sets of protective eyewear have been tested in x-ray fields using anthropomorphic phantoms to simulate the patient and clinician in two centres. The experiments performed have determined DRFs from simulations of interventional procedures by measuring doses to the eyes of the phantom representing the clinician, using TLDs in Glasgow, Scotland and with an electronic dosemeter in Gothenburg, Sweden. During interventional procedures scattered x-rays arising from the patient will be incident on the head of the clinician from below and to the side. DRFs for x-rays incident on the front of lead glasses vary from 5.2 to 7.6, while values for orientations similar to those used in the majority of clinical practice are between 1.4 and 5.2. Specialised designs with lead glass side shields or of a wraparound style with angled lenses performed better than lead glasses based on the design of standard spectacles. Results suggest that application of a DRF of 2 would provide a conservative factor that could be applied to personal dosemeter measurements to account for the dose reduction provided by any type of lead glasses provided certain criteria relating to design and consistency of use are applied.
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| 6. |
- Sandblom, Viktor, 1987, et al.
(författare)
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Evaluation of eye lens doses received by medical staff working in interventional radiology at sahlgrenska university hospital
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Background: The International Commission on Radiological Protection (ICRP) recently lowered their recommended occupational eye lens dose limit from 150 mSv in a year to 20 mSv in a year, averaged over a defined period of 5 years. Aim: The main aim of the present study was to investigate the eye lens doses received by the interventional staff at Sahlgrenska University Hospital. Another aim was to evaluate whether the dose recorded by the PDM, a dosimeter worn at thorax height, could be used as an indicator of eye lens dose. Material and Methods: To prepare for the personnel eye lens dose assessments, phantom measurements were carried out. These preparations included deciding the optimal position of an eye lens dosimeter, evaluation of different models of lead glasses and estimation of a ratio between the eye lens dose and the dose recorded by the PDM. Personnel eye lens doses were assessed using TL-dosimeters held by individual headbands worn by staff members at the Catheterization Laboratory at the department of Cardiology and at the division of Peripheral Interventional Radiology at the department of Radiology at Sahlgrenska University Hospital for one month. Staff members also wore a PDM at thorax height outside their lead apron. Results and Discussion: Materials with an equivalent lead thickness of 0.75 mm block over 95% of incident radiation but the lead glasses evaluated (0.75 mm) reduced the eye lens dose by only 30-88% due to radiation back scattered in the head and oblique incident radiation. Many operators reported annual eye lens doses of over 10 mSv. The eye lens doses of nurses were generally much lower. The ratios between equivalent doses recorded by TLD and PDM were as expected higher for nurses than for operators but the ratios varied also between different operators. Conclusions: The estimations of annual doses have uncertainties and the lens doses of operators are high enough to cause concern. Based on the results of the present study, operators might be recommended to wear lead glasses in the future. Estimating eye lens dose from the dose recorded by the PDM is difficult. This method includes large uncertainties. The PDM should instead be used to indicate whether a more precise measurement is necessary.
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- Sandblom, Viktor, 1987, et al.
(författare)
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Evaluation of the impact of a system for real-time visualisation of occupational radiation dose rate during fluoroscopically guided procedures
- 2013
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 33:3, s. 693-702
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Tidskriftsartikel (refereegranskat)abstract
- Optimisation of radiological protection for operators working with fluoroscopically guided procedures has to be performed during the procedure, under varying and difficult conditions. The aim of the present study was to evaluate the impact of a system for real-time visualisation of radiation dose rate on optimisation of occupational radiological protection in fluoroscopically guided procedures. Individual radiation dose measurements, using a system for real-time visualisation, were performed in a cardiology laboratory for three cardiologists and ten assisting nurses. Radiation doses collected when the radiation dose rates were not displayed to the staff were compared to radiation doses collected when the radiation dose rates were displayed. When the radiation dose rates were displayed to the staff, one cardiologist and the assisting nurses (as a group) significantly reduced their personal radiation doses. The median radiation dose (Hp(10)) per procedure decreased from 68 to 28 μSv (p = 0.003) for this cardiologist and from 4.3 to 2.5 μSv (p = 0.001) for the assisting nurses. The results of the present study indicate that a system for real-time visualisation of radiation dose rate may have a positive impact on optimisation of occupational radiological protection. In particular, this may affect the behaviour of staff members practising inadequate personal radiological protection.
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| 8. |
- Sandblom, Viktor, 1987, et al.
(författare)
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Evaluation of the impact of a system for real-time visualisation of occupational radiation dose rate during fluoroscopically guided procedures
- 2013
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Ingår i: Nationellt möte om sjukhusfysik 2013, 13-14 november 2013, Varberg.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Optimisation of radiological protection for operators working with fluoroscopically guided procedures has to be performed during the procedure, under varying and difficult conditions. The aim of this study was to evaluate the impact of a system for real-time visualisation of radiation dose rate on optimisation of occupational radiological protection during fluoroscopically guided procedures. Individual radiation dose measurements, using a system for real-time visualisation, were performed in a cardiology laboratory for three cardiologists and ten assisting nurses. Radiation doses collected when the radiation dose rates were not displayed to the staff (period 1) were compared to radiation doses collected when the radiation dose rates were displayed (period 2). The results showed that when the radiation dose rates were displayed to the staff, one cardiologist and the assisting nurses (as a group) significantly reduced their personal radiation doses. The median radiation dose ((Hp(10)) per procedure decreased from 68 to 28 μSv (p=0.003) for this cardiologist and from 4.3 to 2.5 μSv (p=0.001) for the assisting nurses. The results of the present study indicate that a system for real-time visualisation of radiation dose rate may have a positive impact on optimisation of occupational radiological protection. In particular, this may affect the behaviour of staff members practising inadequate personal radiological protection.
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- von Wrangel, Alexa, 1967, et al.
(författare)
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Fluoroscopically guided percutaneous vertebroplasty: assessment of radiation doses and implementation of procedural routines to reduce operator exposure.
- 2009
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 50:5, s. 490-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Percutaneous vertebroplasty (PVP) is a fluoroscopically guided procedure for the treatment of painful vertebral compression fractures and metastases. Routine legal personal dosimetry repeatedly showed dosimeter doses exceeding 1 mSv/month for the only radiologist performing PVP at our hospital. Based on the nature of the procedure, this raised concern about potentially high doses to the eyes and fingers. PURPOSE: To assess radiation doses to the operator, and to evaluate possibilities for dose reduction. MATERIAL AND METHODS: Measurements of scattered radiation in simulated thoracic and lumbar PVP procedures were performed using two anatomical phantoms--thorax and lower trunk--and a radiation survey meter. The standard position of the operator was determined as being 50 cm from the irradiated area of the phantom. The protection ability of lead-free gloves was evaluated during the simulations. Operator doses to fingers and eyes during 10 clinical PVP procedures performed by a single operator were measured, and the annual dose was calculated. Routine personal dosimetry was performed using thermoluminescent dosimeter (TLD) badges beneath the lead apron, and doses to fingers and eyes were measured with small TLD tablets. RESULTS: During simulations, the measured operator dose rate arising from lateral fluoroscopy at the thorax and lumbar level was reduced by a factor of 4-5 when the X-ray tube was moved from the operator's side of the patient to the opposite side. Wearing protective gloves reduced radiation dose to the hands by 30-40%. The mean doses arising from the 10 clinical PVP procedures to the right and left hands, using protection gloves, were 2.0 mSv and 4.8 mSv, respectively. The mean dose to the eyes was 0.23 mSv. The mean effective dose to the patients was 12 mSv. CONCLUSION: Placing the X-ray tube on the side of the patient opposite to the operator and the use of radiation protection gloves significantly reduces radiation exposure to the operator. In phantom simulations, the dose was reduced by a factor of 4-5. Knowledge of fluoroscopy equipment, radiation physics, and protection is essential in order to reduce exposure.
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