Background and purpose: Increasing number of patients undergoing x-ray examinations has created a global concern due to the deleterious biological effects associated with x-ray exposure. Adherence to ionizing radiation protection principles could be of great benefit in decreasing these effects. Accordingly, the aim of this study was to survey radiation protection in diagnostic x-ray imaging in Iran using systematic review of published articles. Materials and methods: Without any time limitation, some databases including SID, Magiran, IranMedex, Irandoc, Google-Scholar, Medlin, Embase and PubMed were searched. A total of 122 articles was obtained during the primary research. After elimination of duplicate and irrelevant articles, 39 articles (published in 1997 to 2015) were selected for final review. Results: The researches were performed in conventional radiology centers (n=24), dental radiography (n= 8), nuclear medicine (n=2), mammography (n= 1), computed tomography (n=1), dental radiography and radiology (n= 1), and total diagnostic X-ray departments (n= 2). Totally, 874 diagnostic centers and 1677 radiographers were studied. These studies revealed undesirable level of radiation protection regarding the use of shielding tools for patients, radiation collimation, use of film bag in dental radiography, and quality control programs. But, environmental radiation doses and the use of film bag in radiology centers were found to be in appropriate level. Conclusion: Despite increasing application of x-ray in medical diagnosis, radiation protection did not considerably change in Iran. So a national strategic program on radiation protection seems to be necessary. Such programs must be developed by ministry of health and radiation protection affairs of national atomic energy organization and its administration must be monitored permanently.

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Radiation Protection in Diagnostic X-Ray Imaging Departments in Iran: A Systematic Review of Published Articles

Introduction Quality control (QC) techniques are used in monitoring and maintenance of the components of an x-ray system. QC of radiology devices plays a significant role in reduction of medication dose and optimization of image quality. This study aimed to conduct QC tests on randomly selected radiology devices, installed in diagnostic imaging departments of Iran. Materials and Methods In total, quality control tests were conducted on 51 conventional radiology devices installed in 20 cities of Iran in order to assess the accuracy of peak kilovoltage  (kVp), exposure time, exposure linearity and reciprocity, reproducibility of exposure and determination of half-value layer (HVL) using a calibrated Mult-O-Meter. Results In this study, 38.6% of devices had intolerable variance of kVp accuracy. The results of 34.5% of devices were out of the acceptable limits in exposure time accuracy test. In 46.7% and 53.1% of devices, variance was greater than the acceptable range for exposure linearity and exposure reciprocity, respectively. In terms of reproducibility of exposure test, the reproducibility variance and percentage of tube output variations in 19.4% of devices exceeded the limits. Moreover, the thickness of first HVL was lower than the acceptable limit in 14.7% of devices. Conclusion According to the results of this study, there were wide variations in QC test results, perhaps mainly due to the fact that it is not an obligation to implement QC programs in Iran. The most important problems were non-reciprocity of exposure, nonlinearity of exposure with milliampere-second (mAs), kVp and timer inaccuracy. Involvement of medical physicists, radiologists and radiographers in the implementation of QC programs at various stages of development, installation and use of equipment should enable the gradual improvement in equipment performance.

http://ijmp.mums.ac.ir/article_8402_38e0e6039ea22b76e83b188201be4a56.pdf

Quality Control Assessment of Conventional Radiology Devices in Iran

Introduction Application of quality control (QC) programs at diagnostic radiology departments is of great significance for optimization of image quality and reduction of patient dose. The main objective of this study was to perform QC tests on stationary radiographic X-ray machines, installed in 14 hospitals of Kerman province, Iran. Materials and Methods In this cross-sectional study, QC tests were performed on 28 conventional radiographic X-ray units in Kerman governmental hospitals, based on the protocols and criteria recommended by the Atomic Energy Organization of Iran (AEOI), using a calibrated Gammex QC kit. Each section of the QC kit incorporated different models. Results Based on the findings, kVp accuracy, kVp reproducibility, timer accuracy, timer reproducibility, exposure reproducibility, mA/timer linearity, and half-value layer were not within the acceptable limits in 25%, 4%, 29%, 18%, 11%, 12%, and 7% of the evaluated units (n=28), respectively. Conclusion As radiographic X-ray equipments in Kerman province are relatively old with a high workload, it is recommended that AEOI modify the current policies by changing the frequency of QC test implementation to at least once a year.

http://ijmp.mums.ac.ir/article_7142_398ca2211095bcaf7d9360b605cfe1ba.pdf

Quality Control Assessment of Radiology Devices in Kerman Province, Iran

One of the most important steps in the optimization process in diagnostic imaging is the quality control (QC) of digital radiology devices. The defects of irradiation diagnostic devices in the framework of QC programs were assessed in imaging centers of Tehran province. To perform this schedule, various parameters such as kVp, milli-Ampere (mA), irradiation time, HVL, and additional filters were evaluated by three qualitative control tests. By using Pehamed phantom, Piranha dosimeter, and response time index, the QC of three radiological devices from three different companies—Samsung, Spellman, and Philips—was measured for the first time in Iran. The data obtained through the imagej software were analyzed. Different parameters including dynamic range, contrast, spatial resolution, beam quality, and homogeneity were compared from three devices. The HVL for Al was measured at 2.85 mm over the beam quality. Increasing the voltage increased the HVL so that the constant coefficients for PMX-III and a new electronic multimeter were 0.0787 and 0.0786, correspondingly. Also by raising dose, the irradiation index increased for different kVp and Al-HVL. The pixel values in different ROIs were assessed as there was no discrepancy at the center, but the greatest difference was emerged by 5.329 on the left. Of the pair of lead lines available in the phantom with size of 0.5–5 lp/mm at 45$$^\circ $$, 2.8 line pairs were completely separate to determine the resolution. Also, of the 16 copper sheets with thicknesses from 0 to 3.5, all sheets with thicknesses of 0.36 to 3.48 mm were visible. The coefficient of variation (CV) and the noise fluctuations were calculated for the adjusted voltage, irradiation time, and the output dose. At 100 mA, the maximum CV of the output dose was 0.0074 for 90 kVp-80 ms. The outcomes demonstrated that the Philips digital imaging system is of fairly good quality in all QC tests. Comparatively, the patient absorbed dose with the Spellman X-ray machine was less than with the other two devices. By recorded doses in assessment of linearity detector response, the Samsung and Philips machines demonstrated a great regression coefficient of 99% at different exposures. Improving quality control standards may improve diagnostic quality, reduce the number of repeated tests, and reduce patient exposure.

Quality control assessment of Philips digital radiography and comparison with Spellman and Samsung systems in Tehran Oil Ministry Hospital

Background: The use and effectiveness of traditional lead gonad shields in pediatric pelvic radiography has been challenged by several literatures over the past two decades. The aim of this study was to develop a new radioprotective gonad shields to be use in pediatric pelvic radiography. Materials and Methods: The commercially available 0.06 mm lead equivalent bismuth garment has cropped squarely and used as ovarian shield to cover the entire region of pelvis. In order to prevent deterioration of image quality due to beam hardening artifacts, a 1-cm foam as spacer was located between the shield and patients pelvis. Moreover, we added a lead piece at the cranial position of the bismuth garment to absorb the scatter radiations to the radiosensitive organs. In girls, 49 radiographs with shield and 46 radiographs without shield was taken. The radiation dose was measured using thermoluminescent dosimeters (TLDs). Image quality assessments were performed using the European guidelines. For boys, the lead testicular shields was developed using 2 cm bismuth garment, added to the sides. The prevalence and efficacy of testicular shields was assessed in clinical practice fromFebruary 2016 to June 2016. Results: Without increasing the dose to the breast, thyroid and the lens of the eyes, the use of bismuth shield has reduced the entrance skin dose(ESD) of the pelvis and radiation dose to the ovaries by 62.2% and 61.7%, respectively (P<0.001). Image quality remained diagnostically acceptable in all shielded and non-shielded images, without non-diagnostic or poor quality image. In boy patients, the prevalence of shielding in lead and developed testicular shields were obtained 63.25% and 19.74%, respectively; the accuracy positioning of the shield 90% and 34%, as well as. Conclusion: The ovarian shield designed in this study has significantly reduced the radiation dose to the ovaries without adversely affecting diagnostically image quality. The testicular shield has improved the accuracy positioning of the shield. These developed shields have potential to be use in clinical practice.

http://ijp.mums.ac.ir/article_8633_890061c9e00ee8449c5084162fbc32e4.pdf

Radioprotection to the Gonads in Pediatric Pelvic Radiography: Effectiveness of Developed Bismuth Shield

Introduction In radiography, dose and image quality are dependent on radiographic parameters. The problem is caused from incorrect use of radiography equipment and from the radiation exposure to patients much more than required. Therefore, the aim of this study was to implement a quality-control program to detect changes in exposure parameters, which may affect diagnosis or patient radiation dose. Materials and Methods This cross-sectional study was performed on seven stationary X-ray units in sixhospitals of Lorestan province. The measurements were performed, using a factory-calibrated Barracuda dosimeter (model: SE-43137). Results According to the results, the highest output was obtained in A Hospital (M1 device), ranging from 107×10-3 to 147×10-3 mGy/mAs. The evaluation of tube voltage accuracy showed a deviation from the standard value, which ranged between 0.81% (M1 device) and 17.94% (M2 device) at A Hospital. The deviation ranges at other hospitals were as follows: 0.30-27.52% in B Hospital (the highest in this study), 8.11-20.34% in C Hospital, 1.68-2.58% in D Hospital, 0.90-2.42% in E Hospital and 0.10-1.63% in F Hospital. The evaluation of exposure time accuracy showed that E, C, D and A (M2 device) hospitals complied with the requirements (allowing a deviation of ±5%), whereas A (M1 device), F and B hospitals exceeded the permitted limit. Conclusion The results of this study showed that old X-ray equipments with poor or no maintenance are probably the main sources of reducing radiographic image quality and increasing patient radiation dose.

http://ijmp.mums.ac.ir/article_4770_f629c152d1c834f377e79bec6678f774.pdf

The Evaluation of Conventional X-ray Exposure Parameters Including Tube Voltage and Exposure Time in Private and Governmental Hospitals of Lorestan Province, Iran

The inevitable use of medical imaging examinations and lack of a suitable alternative lead to the need to control and minimize the amount of radiation from such artificial medical sources. To assess the relation between exposure parameters and lifetime of radiology devices, quality control tests were carried out on 13 radiology devices in 11 general hospitals. In this study, a barracuda dosimeter, SE-43137 Sweden, was calibrated to measure and record the quantities of kVp, mAs and exposure parameters. In all the devices using applying the minimum and maximum values of kVp, the minimum and maximum values of the internal resistances were calculated. The lowest mR/mA for the device C was observed at a flow rate of 200 mA (equal to 2,425), while the highest value was for the device A (2) at a current intensity of 200 mA (equal to 14.625). By increasing the age of the device, the output of the device is reduced. Therefore, to compensate for this decrease in the output, higher exposure conditions are usually applied to the device, which can greatly increase the damage to the device.

https://jbpe.sums.ac.ir/article_46621_dd575d99d25ff6d5835de2ec1abf9255.pdf

Fataneh Nemati

Papers

The Evaluation of Conventional X-ray Exposure Parameters Including Tube Voltage and Exposure Time in Private and Governmental Hospitals of Lorestan Province, Iran

A Survey on Exposure Parameters Variation due to Aging in Radiology Devices.