Cosmic rays are the primary source of the daily exposure of aircrew and passengers to ionising radiation. This study aims to estimate the effective doses of ionising radiation for aircraft crews in Bosnia and Herzegovina by taking into consideration factors such as flight duration and altitude, as well as the geographical position of airports. The CARI-7 algorithm and neural network method were used in the analysis of data obtained from the Sarajevo International Airport. The results show that the estimated annual effective doses in 2021 range from 0.06 to 10 mSv for flights to and from Belgrade and Dubai, respectively. Both linear regression and neural network models were developed to predict the effective dose based on flight duration, average altitude, latitude and maximum altitude. The findings reveal that flight duration is the most statistically significant factor, followed by average altitude, latitude and maximum altitude.

Occupational exposure in Bosnia and Herzegovina is regulated by the national regulation on radiation protection for occupational and public exposure. All radiation workers are required to be monitored using whole body passive thermoluminescent dosemeters and, in case of non-uniform external exposures, by dosemeters that would indicate dose to the most affected body parts. Exposed workers are almost exclusively employed in the medical field, and some of them work in nuclear medicine departments where they handle unsealed radioactive sources. Introduction of the positron emission tomography-computed tomography (PET-CT) in two largest clinical centers in the country was expected to cause the increase of equivalent doses to hands received by staff handling the positron emitting radionuclides. Hence, routine monitoring of finger doses became a necessity. The purpose of this study was to evaluate the available data on monitoring with ring dosemeters during PET-CT procedure in two hospitals in Bosnia and Herzegovina and compare them with other practices in the nuclear medicine department, as well as with the results of monitoring in other countries. In general, results confirm that effective doses, as well as equivalent doses to hands, are well below annual dose limits. Finger dosemeters have been proven to be an invaluable asset in the incidental situations that sometimes occur in nuclear medicine departments. Different number of patients and differences in injection methodologies are identified as a possible source of differences between doses in two hospitals. Overall, routine evaluation of doses to hands provides a sound basis for possible optimization processes, as well as confirmation of good practices.

Computed tomography (CT) is a diagnostic imaging process that uses ionising radiation to obtain information about the interior anatomic structure of the human body. Considering that the medical use of ionising radiation implies exposing patients to radiation that may lead to unwanted stochastic effects and that those effects are less probable at lower doses, optimising imaging protocols is of great importance. In this paper, we used an assembled 3D-printed infant head phantom and matched its image quality parameters with those obtained for a commercially available adult head phantom using the imaging protocol dedicated for adult patients. In accordance with the results, an optimised scanning protocol was designed which resulted in dose reductions for paediatric patients while keeping image quality at an adequate level.

Contouring, planning and dose calculation in treatment planning systems (TPS) are based on computedtomography (CT) images. Therefore, it is important to have developed, optimized and adapted scanning protocolsfor specific anatomic regions and special radiotherapy modalities such as stereotactic radiosurgery (SRS). The aimof this study was to determine influence of tube voltage, field of view size (FOV) and reconstruction kernels on CTnumbers and the resulting radiotherapy (RT) dose calculation.This study was performed at Clinic of Oncology, Clinical Center University of Sarajevo. Verification electrondensity and CT number values was performed using CIRS Thorax 002LFC phantom, while anthropomorphic CIRS038 phantom for stereotactic end-to-end verification was used for the purpose of dose plan calculation analysis withlarge bore CT simulator Canon Aquillion LB.The significant correlation between the tube voltage and the measuredvalues of CT numbers is significant for all materials (p < 0.05), except for water (p = 0.310). No significantcorrelation between FOV and obtained values of CT numbers was found in any of the evaluated tissue equivalentmaterials. Evaluating the impact of reconstruction kernels on Hounsfield units (HU), significant deviations werefound for the FC62, FC68 and FC07 reconstruction kernels. Also, analyzing the influence of reconstruction kernelson the RT dose calculation, the extreme values are associated with Dmin/D in PTV for kernels FC41 and FC68, wheredeviations from the values obtained using the baseline scanning parameters were -1.3% and -1.9%. For deviation of1 HU in muscle tissue of CIRS 002LFC, the calculated Dmin/D in PTV of CIRS STEEV phantom will reduce by0.79%. Similarly, the reduction of D₉₈ and D₂ would be 6.8 cGy and 3.03 cGy for 1 HU, respectively. Change of thereconstruction kernels caused differences of 0.4% in Dmin/D calculation in clinical target volume (CTV).CT scanning and reconstruction parameters may affect Hounsfield units, which could have an impact on dosecalculations in RT plan. Hence, it is recommended to standardize the scanning protocol used in calibration curvegeneration for TPS. One should avoid use of different tube voltages and kernels, while according to this study, thechange of FOV will have no impact on dose calculations

For more than two years, coronavirus disease 19 (COVID-19) has represented a threat to global health and lifestyles. Computed tomography (CT) imaging provides useful information in patients with COVID-19 pneumonia. However, this diagnostic modality is based on exposure to ionizing radiation, which is associated with an increased risk of radiation-induced cancer. In this study, we evaluated the common dose descriptors, CTDIvol and DLP, for 1180 adult patients. This data was used to estimate the effective dose, and risk of exposure-induced death (REID). Awareness of the extensive use of CT as a diagnostic tool in the management of COVID-19 during the pandemic is vital for the evaluation of radiation exposure parameters, dose reduction methods development and radiation protection.

Introduction: Axial-loaded magnetic resonance imaging (MRI), which can simulate an upright position of the patient may cause a significant reduction of the dural sac cross-sectional area (DCSA) compared with standard MRI, thus providing valuable information in the assessment of the lumbar spinal canal. The purpose of this study was to investigate excessiveness of the change in DCSA and depth of lateral recesses (DLRs) before and after axial-loaded imaging in relation to body mass index (BMI) of the subjects.Methods: Twenty patients were scanned to evaluate DCSA and DLR at three consecutive lumbar spine intervertebral disc levels (L3/4, L4/5, and L5/S1) on conventional-recumbent MRI, and after axial loading were applied.Results: Axial-loaded MRI demonstrates a significant difference of DSCA in comparison to conventional MRI. Furthermore, results show a significant correlation between the DCSA and BMI on level L3/L4, both before and after axial loading MRI. With axial loading, there is a reduction of DSCA of 12.2%, 12.1%, and 2.1% at the levels L3/L4, L4/L5, and L5/S1, respectively. After axial loading has been applied, the depth of the neural foramen has been reduced by an average of 10.1%.Conclusion: Axial-loaded MRI reduces DCSA and DLRs in comparison to standard MRI. Information obtained in this way may be useful to explain the patient’s symptomatology and may provide an additional insight that can influence the treatment decision plan accordingly.