Background: The health implication of exposure to gamma radiation in the outdoor and indoor environments has become a major concern worldwide. Methods: This study was conducted in the city of Birjand where three stations and buildings were randomly selected to measure the background radiation in outdoor and indoor places; for this purpose, GM detector (X5C plus) was used. All dose rates on the display of the survey meter were recorded, and the mean of all data in each station and buildings was computed and taken as the measured dose rate of that particular station. Results:The average dose rate of background radiation was 71.8 nSv/h for outdoor and 82.0 nSv/h for indoor environments, and the maximum and minimum dose rates were 79.6 nSv/h and 61.7 nSv/h for outdoor measurements and 112.9 nSv/h and 70.8 nSv/h for indoor measurements, respectively. Conclusions:The results revealed that the annual effective dose is 0.49 mSv, which is similar to that of the global level (0.48 mSv).

Background The concept of diagnostic reference level (DRL) is considered a regular method to optimize radiation protection in diagnostic imaging system. The objective of implementing a reference level for dose is to produce high-quality images by applying a minimum dose of radiation based on the As Low As Reasonably Achievable (ALARA) principle. Therefore, this study aimed to evaluate the status of radiation protection in diagnostic radiology wards of educational hospitals affiliated with Birjand University of Medical Sciences. Methods This study was performed during a period of 11-months in the radiology center of the teaching hospital of Birjand University of Medical Sciences. The studied population included 477 patients who were referred to as clinically indicated x-ray radiography. In order to calculate local DRLs, dose area product (DAP) was measured by a DAP-meter (KERMAX-plus SPD, model 120–131 HS) for 11 devices at educational hospitals affiliated with Birjand University of Medical Sciences. The local DRL values was calculated as 75% of the mean DAP distribution for a specific patient trial at each center. Results DAP for Chest PA examination was gained to be in the range from 0.12 Gy.cm2 to 0.42 Gy.cm2 with an average value of 0.23 Gy.cm2 which is above the value of the reference level (0.12 Gy.cm2) for Chest PA. For Chest lateral the observed DAP was found to be in the range from 0.18 Gy.cm2 to 1.48 Gy.cm2 with an average value of 0.65 Gy.cm2 and are therefore twice the reference value (0.3 Gy.cm2). The higher DRL values (average = 2.73) are for lumbar spine lateral radiography. It is observed that the DRL values of chest PA, abdomen AP and Lumbar spine AP are much lower with the earlier studies. Conclusions The DRLs helps in understanding the current practices in radiographic examinations. Comparison with other hospitals, the scope of dose optimization and ultimately patient dose reduction in hospitals affiliated with Birjand University of Medical Sciences needs further investigation.

Background:The aim of the present study was to evaluate how left ventricular twist and torsion are associated with sex between sex groups of the same age. Materials and Methods: In this analytical study, twenty one healthy subjects were scanned in left ventricle basal and apical short axis views to run the block matching algorithm; instantaneous changes in the base and apex rotation angels were estimated by this algorithm and then instantaneous changes of the twist and torsion were calculated over the cardiac cycle. Results:The rotation amount between the consecutive frames in basal and apical levels was extracted from short axis views by tracking the speckle pattern of images. The maximum basal rotation angle for men and women were -6.94°±1.84 and 9.85°±2.36 degrees (p-value = 0.054), respectively. Apex maximum rotation for men was -8.89°±2.04 and for women was 12.18°±2.33 (p-value < 0.05). The peak of twist angle for men and women was 16.78 ± 1.83 and 20.95± 2.09 degrees (p-value < 0.05), respectively. In men and women groups, the peak of calculated torsion angle was 5.49°±1.04 and 7.12± 1.38 degrees (p-value < 0.05), respectively. Conclusion:The conclusion is that although torsion is an efficient parameter for left ventricle function assessment, because it can take in account the heart diameter and length, statistic evaluation of the results shows that among men and women LV mechanical parameters are significantly different. This study was mainly ascribed to the dependency of the torsion and twist on patient sex.