Comparison of Different Methods for Shielding Design in Computed Tomography

The purpose of this work is to compare different methods for shielding calculation in computed tomography (CT). The BIR-IPEM (British Institute of Radiology and Institute of Physics in Engineering in Medicine) and NCRP (National Council on Radiation Protection) method were used for shielding thickness calculation. Scattered dose levels and calculated barrier thickness were also compared with those obtained by scatter dose measurements in the vicinity of a dedicated CT unit. Minimal requirement for protective barriers based on BIR-IPEM method ranged between 1.1 and 1.4 mm of lead demonstrating underestimation of up to 20 % and overestimation of up to 30 % when compared with thicknesses based on measured dose levels. For NCRP method, calculated thicknesses were 33 % higher (27-42 %). BIR-IPEM methodology-based results were comparable with values based on scattered dose measurements, while results obtained using NCRP methodology demonstrated an overestimation of the minimal required barrier thickness

Mammography practice in Serbia: evaluation and optimisation of image quality and the technical aspects of the mammographic imaging chain

The purpose of this work was to assess mammography practice in Serbia and its appropriateness for both diagnostic service and potential screening by implementing quality control (QC) protocol in three large teaching hospitals. Corrective actions were suggested, accordingly. In addition to technical aspects of QC, image quality was assessed using image grading before and after the introduction of corrective measures. The survey demonstrated considerable variations in technical parameters that affect image quality and patients doses. Average glandular doses ranged from 1.8 to 2.8 mGy, while reference optical density (OD) ranged from 1.0 to 2.6. Image grading resulted in a very high percentage of images with poor quality (12-70 % for cranio-caudal projection and 8-66 % for medio-lateral oblique projection). Main problems were associated with film processing, viewing conditions and OD control. Following introduction of corrective measures, the image grading results were improved in some hospitals, so the percentage of images without any remarks has been increased

Mammography Radiation Dose: Initial Results from Serbia Based on Mean Glandular Dose Assessment for Phantoms and Patients

The primary objective of this study is to investigate the actual mammography dose levels in Serbia and establish a baseline dose database for the future screening programme. The mean glandular dose (MGD) was assessed for standard size breast substituted by 45 mm polymethyl methacrylate (PMMA) phantom and imaged under typical clinical conditions at 30 screen-film mammography facilities. Average MGD was (1.9 +/- 1.0) mGy, with a range of 0.12-5.2 mGy. These results were used for the calculation of the initial diagnostic reference levels in mammography in Serbia, which was set to 2.1 mGy for a standard breast. At some facilities, high doses were observed and the assessed MGD was supplemented by a patient dose survey. MGD was measured for 53 women having a diagnostic mammography in cranio-caudal (CC) and mediolateral oblique (MLO) projections at the largest mammography facilities in Serbia. The parameters recorded were: age, compressed breast thickness, tube potential (in kV), tube loading (in mAs) and the MLO projection angle. The average MGD per image was 2.8 mGy for the CC projection and 4.3 mGy for the MW projection. Dose to breast was compared with dose for PMMA phantoms of various sizes, assessed at the same facilities. The results have indicated that phantom dose values can assist in setting optimisation activities in mammography. Both phantom and patient dose values indicated unnecessary high doses in facilities with an extremely high mammography workload. For these facilities, urgent dose-reduction measures and follow-up actions were recommended

A radiological incident with a radioactive lightning rod source found in a vehicle used by film crewmembers: a case study

An overview of radiological incident involving radiation source from a lightning rod ((152)Eu/(154)Eu), together with dose estimation for individuals exposed to ionising radiation is given in the paper. The cause of the incident was an orphaned source from a lightning rod. The dose received by individuals was assessed using a retrospective dosimetry technique, based on the information on behaviour of individuals and results of dose rate measurements in the vicinity of the source. Several people have been exposed to relatively high dose rates for an extended period of time. The conservatively estimated cumulative dose values for two categories of individuals were 50 and 40 mSv, respectively, which are significantly higher than annual dose limit for public exposure of 1 mSv. The need to identify radioactive sources incorporated in radioactive lightning rods, to maintain control and accountability and to remove and dispose of them properly along with appropriate record keeping in Serbia was highlighted. These activities would reduce the probability of occurrence of radiation incidents in Serbia

Eye lens dosimetry in interventional cardiology: results of staff dose measurements and link to patient dose levels

Workers involved in interventional cardiology procedures receive high eye lens dose if protection is not used. Currently, there is no suitable method for routine use for the measurement of eye dose. Since most angiography machines are equipped with suitable patient dosemeters, deriving factors linking staff eye doses to the patient doses can be helpful. In this study the patient kermaarea product, cumulative dose at an interventional reference point and eye dose in terms of H-p(3) of the cardiologists, nurses and radiographers for interventional cardiology procedures have been measured. Correlations between the patient dose and the staff eye dose were obtained. The mean eye dose was 121 Sv for the first operator, 33 Sv for the second operator/nurse and 12 Sv for radiographer. Normalised eye lens doses per unit kermaarea product were 0.94 Sv Gy(1) cm(2) for the first operator, 0.33 Sv Gy(1) cm(2) for the second operator/nurse and 0.16 Sv Gy(1) cm(2) for radiographers. Statistical analysis indicated that there is a weak but significant (p 0.01) correlation between the eye dose and the kermaarea product for all three staff categories. These values are based on a local practice and may provide useful reference for other studies for validation and for wider utilisation in assessing the eye dose using patient dose values

Good reasons to implement quality assurance in nationwide breast cancer screening programs in Croatia and Serbia: Results from a pilot study

The purpose of this study is to investigate the need for and the possible achievements of a comprehensive QA programme and to look at effects of simple corrective actions on image quality in Croatia and in Serbia. The paper focuses on activities related to the technical and radiological aspects of QA. The methodology consisted of two phases. The aim of the first phase was the initial assessment of mammography practice in terms of image quality, patient dose and equipment performance in selected number of mammography units in Croatia and Serbia. Subsequently, corrective actions were suggested and implemented. Then the same parameters were re-assessed. Most of the suggested corrective actions were simple, low-cost and possible to implement immediately, as these were related to working habits in mammography units, such as film processing and darkroom conditions. It has been demonstrated how simple quantitative assessment of image quality can be used for optimisation purposes. Analysis of image quality parameters as OD, gradient and contrast demonstrated general similarities between mammography practices in Croatia and Serbia. The applied methodology should be expanded to larger number of hospitals and applied on a regular basis. (C) 2009 Elsevier Ireland Ltd. All rights reserved

Radiation Exposure to Nuclear Medicine Staff Involved in Pet/Ct Practice in Serbia

The purpose of this work is to evaluate the radiation exposure to nuclear medicine (NM) staff in the two positron emission tomography-computed tomography centres in Serbia and to investigate the possibilities for dose reduction. Dose levels in terms of H-p(10) for whole body and H-p(0.07) for hands of NM staff were assessed using thermoluminescence and electronic personal dosemeters. The assessed doses per procedure in terms of H-p(10) were 4.2-7 and 5-6 mu Sv, in two centres, respectively, whereas the extremity doses in terms of H-p(0.07) in one of the centres was 34-126 mu Sv procedure(-1). The whole-body doses per unit activity were 17-19 and 21-26 mu Sv GBq(-1) in two centres, respectively, and the normalised finger dose in one centre was 170-680 mu Sv GBq(-1). The maximal estimated annual whole-body doses in two centres were 3.4 and 2.0 mSv, while the corresponding extremity dose in the later one was 45 mSv. Improvements as introduction of automatic dispensing system and injection and optimisation of working practice resulted in dose reduction ranging from 12 up to 67%