Vahid Karami

Bio: Vahid Karami is an academic researcher from Ahvaz Jundishapur University of Medical Sciences. The author has contributed to research in topics: Radiography & Radiation protection. The author has an hindex of 10, co-authored 25 publications receiving 197 citations.

Gonad Shielding during Pelvic Radiography: A Systematic Review and Meta-analysis.

Abstract: BACKGROUND: Gonad shielding has been extensively advocated during pelvic radiography at or below reproductive ages. The popular practice of gonad shielding is placement of a lead shield in the midline of the pelvis. The aim of this study was to address the prevalence of gonad shielding and find out whether the current practice of gonad shielding can be considered as an effective method to reduce radiation exposure in patients undergoing pelvic radiography. METHODS: National and international electronic databases, including PubMed, MEDLIN, EMBASE, and Google-Scholar, were searched up to January 2016. The database searches were supplemented with manual searches of reference lists. Two authors independently assessed the eligibility of all studies and extracted data. RESULTS: The searches yielded a total of 243 publications. After assessing each identified study against specific inclusion exclusion criteria, 18 studies were deemed as relevant for this review. The total prevalence rate of gonad shielding was estimated at 58% (95% CI: 40 to 74%). It was estimated that only 34% (95% CI: 25 to 44%) of the radiographs had correct positioning of the shield. Also, incorrect positioning of the shield was statistically significantly higher in females than males (85% vs. 52 %; P-value < 0.001). CONCLUSIONS: Our study demonstrates that the current practice of gonad shielding during female pelvic radiography should be no longer considered as an effective method to reduce radiation exposure. Training the best qualified radiographers is the key to accurate positioning of the shield in male subjects.

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

Abstract: 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.

Survey of the Use of X-ray Beam Collimator and Shielding Tools during Infant Chest Radiography

Abstract: Background The use of shielding tools and X-ray beam collimator has extensively been advocated as effective methods to reduce radiation exposure to patients underwent radiological procedures. The aim of this study was to address the use of these protection measures during infant chest radiography. Material and Methods 348digital and/or analogue infant chest radiographs were reviewed that performed between October- and December 2015 at four main hospitals of Khuzestan-Iran province to assessment the beam collimation. For each radiograph the area between current and acceptable collimation was calculated. Thirty eight radiographers were deeply interviewed to investigate the actual use of shielding tools and the main reasons for not using of them. Results Only 54 (15.5%) radiographs [33(61%) analogues and 21(39%) digital] have satisfactory collimation. The total means area of diagnostic interest (ADI) and the region outside ADI for each radiograph was estimated 171 and 86 cm2, respectively. The irradiated region outside the ADI was significantly larger in digital than in analogue images (mean of 103 cm2 vs. 54 cm2; P < 0.05). Shielding tools were used regularly only by 5% of radiographers. Conclusion The radiosensitive organs of infants located outside of ADI in hospitals investigated are at risk. Adherence to safety guideline urgently recommends.

The protection knowledge and performance of Radiographers in some hospitals of Ahvaz County

Abstract: Background: Diagnostic radiology is the process of obtaining a high-quality image while minimizing the doses received by patients. Radiographers’ knowledge of protection and safety principles and their correct application plays a significant role in radiation protection. Hence, this study aims to evaluate the radiographers’ protection and safety knowledge, attitude and practice in the radiology wards at several hospitals in Ahvaz County. Materials and Methods: This study is a descriptive and cross sectional one conducted using an observation checklist and a scientific questionnaire, respectively by the researcher and radiographers to evaluate the protection and safety practice and knowledge of radiographers in some selected hospitals in Ahvaz County. The collected data were analyzed, using the SPSS version 20, through descriptive statistics, independent t -test, Pearson correlation test and analysis of variance. Results: A significant correlation exists between r adiographers’ educational level and their protection and safety knowledge and practice. The results shows a significant difference between the protection and safety knowledge among radiographers in the selected hospitals as well as in their attitude and pr actice. It was also revealed that there exist a shortage of lead apron (29%) and a low level of its use even when available; the gonad and thyroid shield and lead partition for mobile radiology were not used at all. Conclusion: The present study confirms the need to highlight protection and safety principles in the departments of radiology to ensure the safety of radiographers and patients. In this regard, supplying protection equipment and holding courses on radiation protecti on are useful.

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

Abstract: 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.

Death of the ALARA Radiation Protection Principle as Used in the Medical Sector.

Abstract: ALARA is the acronym for "As Low As Reasonably Achievable." It is a radiation protection concept borne from the linear no-threshold (LNT) hypothesis. There are no valid data today supporting the use of LNT in the low-dose range, so dose as a surrogate for risk in radiological imaging is not appropriate, and therefore, the use of the ALARA concept is obsolete. Continued use of an outdated and erroneous principle unnecessarily constrains medical professionals attempting to deliver high-quality care to patients by leading to a reluctance by doctors to order images, a resistance from patients/parents to receive images, subquality images, repeated imaging, increased radiation exposures, the stifling of low-dose radiation research and treatment, and the propagation of radiophobia and continued endorsement of ALARA by regulatory bodies. All these factors result from the fear of radiogenic cancer, many years in the future, that will not occur. It has been established that the dose threshold for leukemia is higher than previously thought. A low-dose radiation exposure from medical imaging will likely upregulate the body's adaptive protection systems leading to the prevention of future cancers. The ALARA principle, as used as a radiation protection principle throughout medicine, is scientifically defunct and should be abandoned.

Gonad Shielding during Pelvic Radiography: A Systematic Review and Meta-analysis.

Abstract: BACKGROUND: Gonad shielding has been extensively advocated during pelvic radiography at or below reproductive ages. The popular practice of gonad shielding is placement of a lead shield in the midline of the pelvis. The aim of this study was to address the prevalence of gonad shielding and find out whether the current practice of gonad shielding can be considered as an effective method to reduce radiation exposure in patients undergoing pelvic radiography. METHODS: National and international electronic databases, including PubMed, MEDLIN, EMBASE, and Google-Scholar, were searched up to January 2016. The database searches were supplemented with manual searches of reference lists. Two authors independently assessed the eligibility of all studies and extracted data. RESULTS: The searches yielded a total of 243 publications. After assessing each identified study against specific inclusion exclusion criteria, 18 studies were deemed as relevant for this review. The total prevalence rate of gonad shielding was estimated at 58% (95% CI: 40 to 74%). It was estimated that only 34% (95% CI: 25 to 44%) of the radiographs had correct positioning of the shield. Also, incorrect positioning of the shield was statistically significantly higher in females than males (85% vs. 52 %; P-value < 0.001). CONCLUSIONS: Our study demonstrates that the current practice of gonad shielding during female pelvic radiography should be no longer considered as an effective method to reduce radiation exposure. Training the best qualified radiographers is the key to accurate positioning of the shield in male subjects.

Female gonadal shielding with automatic exposure control increases radiation risks

Abstract: Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose–area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21–51% in the 5-year-old phantom and 17–100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation.

Beam Collimation during Lumbar Spine Radiography: A Retrospective Study

Abstract: Introduction: Collimating the primary beam to the area of diagnostic interest (ADI) has been strongly recommended as an effective method to reduce patient’s radiation dose and to improve image quality during radiology practice. Lack or inadequate collimation results in excessive radiation dose to patients and deterioration image quality. Objective: To assess the quality of beam collimation during lumbar spine radiography at two general hospitals in Ahvaz, Iran. Materials and Methods: We retrospectively reviewed 830 digital antero-posterior (AP) lumbar spine radiographs in term of beam collimation. For each radiograph, the distance between current and optimal collimation was calculated (in cm). The area of ADI and total field size for each radiograph were also calculated (in cm2). Results: The total mean ADI and irradiated region outside ADI for each radiograph were estimated 360 and 454 cm2, respectively. The total irradiated region outside ADI was 1.26 times more than ADI. In contrast to cranial regions outside ADI, caudal regions were more commonly included inside the primary beam (12% vs. 24.4%; P-value <0.005). At least in 62% of radiographs evaluated, ovaries were included in the primary beam. Conclusion: Radiographers should make considerable effort to limit the primary beam to the ADI to reduce patient’s exposure and to increase image quality.