Ali Jomehzadeh

Bio: Ali Jomehzadeh is an academic researcher from Kerman Medical University. The author has contributed to research in topics: Imaging phantom & Effective dose (radiation). The author has an hindex of 6, co-authored 13 publications receiving 120 citations. Previous affiliations of Ali Jomehzadeh include Isfahan University of Medical Sciences & Rafsanjan University of Medical Sciences.

Gamma background radiation measurement in Lorestan province, Iran

Abstract: Background: The exposure of human being to ionize radiation from natural sources is a continuing, inescapable feature of life on earth. Direct measurement of absorbed dose rates in air has been carried out in many countries of the world during the last few decades. Such investigations can be useful for assessment of public dose rates, the performance of epidemiological studies, and keeping reference-data records to ascertain possible changes in the environmental radioactivity duo to nuclear, industrial, and other human activities. Materials and Methods: The measurements of the outdoor and indoor- environmental exposures including cosmic and terrestrial components were accomplished by a portable Geiger Muller detector (RDS -110). The measurements were made during daylight from September to October 2009, in five areas within nine big cities of Lorestan province. In each area, one building was randomly selected for indoor and outdoor measurements. Measurements were made for each region and an average value was used to calculate the exposure rate from gamma background radiation. Results: The results showed the Maximum and minimum outdoor dose rates as 166±44 and 65±8 nSvh-1 in Borujerd and Pol-e- dokhtar, respectively. The average of outdoor dose rates was determined 113±26 nSvh-1. Also the maximum and minimum values of indoor dose were 157±52 and 74±14 nSvh-1 in Borujerd and Pol-e-dokhtar, respectively. The average indoor dose rates were determined as 119±27 nSvh-1. Conclusion: The average annual effective dose for gamma background radiation in Lorestan province has been 0.72 mSv, with the range of 0.3– 0.6 mSv which was more than the global value (0.48 mSv). A poor correlation coefficient between was observed altitude and absorbed dose rates. Iran. J. Radiat. Res., 2011; 9(2): 89­93

Clinical education problems: the viewpoints of nursing and midwifery students in Hormozgan University of Medical Sciences

Abstract: Introduction: Clinical education is a complicated process which may be affected by different factors and variables. Therefore, recognizing the current situation and problems is the first step to minimize these factors. The aim of this study was to determine the viewpoints of nursing and midwifery students in Hormozgan University of Medical Sciences about problems that they have encountered in clinical education. Methods: In this cross-sectional study, 59 bachelor nursing and midwifery students who were in their last semester were involved. The data were collected using a questionnaire with three parts: demographic data clinical education problems (measured by Likert scale) and one open question related to clinical education problems. The collected data were analyzed by SPSS (ver. 13) software. Results: The most important problems in clinical education were lack of welfare facilities (71.2), lack of proper clinical environments (39), lack of educational aids (37.3), lack of facilities in clinical environments (35.6) and lack of skilled clinical trainers (35.6). Conclusion: According to our findings, it is recommended to provide enough facilities and equipments for students in clinical environments and also to employ expert clinical trainers to improve quality of education.

Gonad, bone marrow and effective dose to the population of more than 90 towns and cities of Iran, arising from environmental gamma radiation

Abstract: Background: Since 1996 the assessment of environmental gamma radiation dose in residential areas of Iranian towns and cities has been accomplished for 10 counties. As a practical method and based on the results of a pilot study, in order to attribute the final results to the whole residential area of a town five stations were selected for every town. The location of individual station was studied closely to comply with recommended conditions in the literature. Materials and Methods: RDS-110 was employed to measure gamma dose rate for one hour. Average annual dose rates plus conversion coefficients were employed to estimate gonad, bone marrow, equivalent and effective dose. Result: Minimum and maximum annual bone marrow and gonad dose equivalent attributed to environmental gamma are 0.24 mSvy -1 (for both tissues) and 1.44 and 1.46 mSvy-1, respectively. Conclusion: Average gonad and bone marrow doses for North Khorasan, Boshehr and Hormozgan provinces were less than the corresponding values for normal area. Iran. J. Radiat. Res., 2009; 7 (1): 41­47

A quality assurance program for an amorphous silicon electronic portal imaging device using in-house developed phantoms: a method development for dosimetry purposes

Abstract: Background: Electronic portal imaging devices (EPIDs) play an important role in radiaƟ on therapy portal imaging, geometric and dosimetric verificaƟ ons. A successful uƟ lizaƟ on of EPIDs for imaging and dosimetric purposes requires a reliable quality control process rouƟ ne to be carried out regularly. In this study, two in-house phantoms were developed and analyzed for implementaƟ on in a quality assurance program for dosimetry purposes. Materials and Methods: An amorphous silicon (a-Si) imager (OpƟ Vue500) was used. A low contrast resoluƟ on phantom and an image quality phantom were constructed and implemented. Low contrast resoluƟ on of the EPID was evaluated by counƟ ng the number of holes detectable in the image of phantom using human observers and a soŌ ware. The image quality phantom was used for modulaƟ on transfer funcƟ on, contrast to noise raƟ o and noise level evaluaƟ ons. This phantom contains five sets of high-contrast rectangular bar paƩ erns of variable spaƟ al frequencies and six uniform regions. Results: Although the manual low contrast resoluƟ on method was observer- dependent and insensiƟ ve to arƟ facts, the automaƟ c method was robust and fully objecƟ ve but sensiƟ ve to arƟ facts. The criƟ cal frequency values for 6 and 18 MV were 0.3558±0.006 lp/mm and 0.2707±0.006 lp/mm respecƟ vely. The contrast-to-noise raƟ o was found to be ~ 240% higher for 6 MV compared to 18 MV. Conclusion: The developed phantoms provide a convenient process for periodic performance of an EPID. These phantoms are independent of the EPID system and provide robust tools for conƟ nuous monitoring of image quality parameters as well as dosimetric parameters.