Radijaciono opterećenje pacijenata u konvencionalnoj dijagnostičkoj radiologiji - analiza radiološke prakse u Srbiji

X-rays are by far most significant contributor to total population dose from man-made sources of radiation. Diagnostic reference levels provide frameworks to reduce variability. The aim of this study is to establish, for the first time, a baseline for national diagnostic reference levels in Serbia for the most common X-ray examination types. Dose estimates are based on measurements of kerma-area product and Entrance surface air kerma for at least ten patients for each examination type, in each of 16 randomly selected hospitals in Serbia. Mean, median and third quartile values of patient doses are reported. Results have shown wide variation of mean hospital doses. Entrance surface doses were compared with previously published diagnostic reference levels. Doses for all studied examination types except chest radiography were within European DRL. The reasons for dose variation are discussed. The findings emphasize the importance of regular patient dose measurement to ensure that patient doses are kept as low as reasonable achievable.Primena jonizuju}eg zračenja u dijagnostičkoj radiologiji je najznačajniji činilac u ukupnom radijacionom optere}enju populacije. Dijagnostički referentni nivoi obezbedjuju okvir za smanjenje varijabilnosti u ovoj oblasti. Cilj rada je da se odrede osnovne vrednosti nacionalnih dijagnosti~kih referentnih nivoa u Srbiji za najfrekventnije procedure u konvencionalnoj dijagnostičkoj radiologiji. Procena doza zasnovana je na merenju proizvoda kerme i površine (KAP) i kerme na površini kože pacijenta (ESAK), za najmanje 10 pacijenata za svaku proceduru u 16 slučajno odabranih bolnica u Srbiji. Odredjene srednje vrednosti pacijentnih doza, medijane i trećih kvartila ukazuju na velike varijacije u izloženosti pacijenata u različitim bolnicama. Izmerene vrednosti ESAK uporedjene su sa evropskim dijagnostičkim referentnim nivoima. Analizirani su uzroci varijacija pacijentnih doza i mogućnosti za smanjenje radijacionog optere}enja populacije od dijagnostičke radiologije. Rezultati ukazuju i na značaj redovnog merenja pacijentnih doza u dijagnostičkoj radiologiji

An Assessment of Scattered Radiation During Fluoroscopic Procedures in Diagnostic Radiology

The results of measurements of scattered radiation in the vicinity of a fluoroscopic X-ray facility are presented in this paper. Two different fluoroscopic systems, one with an undercouch tube and one with an overcouch tube, were compared. The dose rate was measured during the simulation of a fluoroscopy procedure, using an ionization chamber as a dosemeter. The distribution of scattered radiation has been determined and results show a much higher dose rate in cases of an overcouch tube arrangement. When X-ray units with an undercouch tube are concerned, under same exposure conditions, the dose rate is higher in cases of a vertical beam. Prior to the measurements, the ionization chamber was examined in order to evaluate its suitability as a survey meter used in diagnostic radiology. Measurements show that below 1.2 s, the ionization chamber gives an underestimation of dose rates. Therefore, in order to perform accurate measurements using this instrument, exposure times should be above 1.2 s

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

First results on patient dose measurements from conventional diagnostic radiology procedures in Serbia and Montenegro

The objective of this work is to assess patient doses for the most frequent X-ray examinations for the first time in Serbia and Montenegro. A total of 510 procedures for 11 different examination categories in 3 general hospitals were analysed. Mean and median entrance surface air kerma (ESAK) and kerma area product (KAP) values followed by mean effective doses were reported. Using X-ray tube output data, ESAK for each radiographic examination was calculated, as well as the effective dose for each patient. Except for chest PA examination, all estimated doses are less than stated European and International Atomic Energy Agency (IAEA) reference levels for simple radiographic examinations. For complex examinations involving fluoroscopy and radiography total KAP was measured and contributions from fluoroscopy and radiography were assessed. The study of KAP confirms that the dose level for complex fluoroscopy investigations is closely related to the technique and individual patient variation in terms of fluoroscopy time and number of radiography exposures. The obtained values are comparable to those reported in the UK. Survey data are aimed aid development of a national quality control and radiation protection programme for medical exposures

Patient dosimetry in diagnostic radiology and dose measurement I practice - A pilot survey

The estimation of doses received by patients undergoing radiological examinations is presented. The results are presented, in terms of entrance surface doses (ESD) and effective dose to patients undergoing common X-ray examination.Conference on Applied Physics in Serbia, May 27-29, 2002, Belgrade, Yugoslavi

Patient dosimetry in diagnostic radiology and dose measurement I practice - A pilot survey

The estimation of doses received by patients undergoing radiological examinations is presented. The results are presented, in terms of entrance surface doses (ESD) and effective dose to patients undergoing common X-ray examination.Conference on Applied Physics in Serbia, May 27-29, 2002, Belgrade, Yugoslavi

Patient doses for barium meal examination in Serbia and Montenegro and potentials for dose reduction through changes in equipment settings

Patient doses for barium meal examination performed at three general hospitals, in Serbia and Montenegro were measured using a kerma-area product (KAP) meter. The results were analysed in order to obtain dose-related parameters. Although the observed doses were within the range reported in other studies, intra-hospital and inter-hospital dose variations were significant. Mean KAP values for total examination in three hospitals were 8.4, 24.4 and 13.9 Gy cm(2), respectively. Contribution from fluoroscopy was greater than from radiography. Factors contributing to the increased dose delivery were determined and the recommendations on radiographic techniques were made. Changes, in radiography settings allowed dose reduction up to 48% in the radiographic part of examination, that is. up to 12% in total dose without loss of image quality. In addition, fluoroscopy time was noted as the second major contributor to the dose variations. The results demonstrated the need for standardisation of practice for barium meal examination in the country.2nd Malmo Conference on Medical X-Ray Imaging, Apr 23-25, 2004, Malmo Univ Hosp, Malmo, Swede

Patient dosimetry in diagnostic radiology

The objective of this work is to assess patient organ doses, effective doses and entrance surface doses in conventional diagnostic radiology procedures for standard adult patient. The survey consists of measurements of doses delivered to 239 patients in nine types of X-ray examinations. Three types of data were collected: X-ray machine data, patient data, and output measurements. Entrance surface dose was assessed based on the survey data and subsequently, using conversion coefficients, the organ doses and effective doses were calculated. Values of the entrance surface dose and the effective dose were estimated to be 0.4 to 5.8 mGy and 0.03 to 3.00 mSv for different examinations. Derived doses were compared with recommended general diagnostic reference levels. The impact of examination parameters on dose values was discussed. Except for posterior-anterior chest examination, all estimated doses are lower than stated reference levels. Survey data are aimed at helping development of national quality control and radiation protection programmed for medical exposures

Quality assurance in diagnostic radiology with x-rays

The concept of radiographic quality assurance focuses primarily on the enhancement of radiographic image quality and on the reduction of unnecessary patient exposure by using quality administrative procedures and quality control techniques.Conference on Applied Physics in Serbia, May 27-29, 2002, Belgrade, Yugoslavi