• Journal of Radiation Protection and Research
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• v.47 no.2
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• pp.93-98
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• 2022

Background: This study aims to derive the characteristics of each work type for industrial radiography based on empirical evidence through expert advice and a survey of radiation workers of various types of industrial radiography. Materials and Methods: According to a Korean report, work types of industrial radiography are classified into indoor tests, underground pipe tests, tests in a shielded room (radiographic testing [RT] room test), outdoor field tests, and outdoor large structure tests. For each work type, exposure geometry and radiation sources were mainly identified through the expert advice and workers' survey as reliable empirical evidence. Results and Discussion: The expert advice and survey results were consistent as the proportion of the work types were high in the order of RT room test, outdoor large structure test, underground pipe test, outdoor field test, and indoor test. The outdoor large structure test is the highest exposure risk work type in the industrial radiography. In most types of industrial radiography, radiation workers generally used ¹⁹²Ir as the main source. In the results of the survey, the portion of sources was high in the order of ¹⁹²Ir, X-ray generator, ⁶⁰Co, and ⁷⁵Se. As the exposure geometry, the antero-posterior geometry is dominant, and the rotational and isotropic geometry should be also considered with the work type. Conclusion: In this study, through expert advice and a survey, the external exposure characteristics for each work type of industrial radiography workers were derived. This information will be used in the reconstruction of organ dose for health effects assessment of Korean radiation workers.

• Journal of Trauma and Injury
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• v.35 no.3
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• pp.215-218
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• 2022

The rectum is the least frequently injured organ in trauma, with an incidence of about 1% to 3% in trauma cases involving civilians. Most rectal injuries are caused by gunshot wounds, blunt force trauma, and stab wounds. A 46-year-old male patient was crushed between two vehicles while he was working. He was hemodynamically unstable, and the Focused Assessment with Sonography for Trauma showed hemoperitoneum and hemoretroperitoneum; therefore, damage control surgery with pelvic packing was performed. A subsequent whole-body computed tomography scan showed a displaced pelvic bone and sacrum fracture. There was evidence of an anorectal full-thickness laceration and urethral laceration. In second-look surgery performed 48 hours later, the pelvis was stabilized with external fixators, and it was decided to proceed with loop sigmoid colostomy. A tractioned rectal probe with an internal balloon was positioned in order to approach the flaps of the rectal wall laceration. On postoperative day 13, a radiological examination with endoluminal contrast injected from the stoma after removal of the balloon was performed and showed no evidence of extraluminal leak. Rectosigmoidoscopy, rectal manometry, anal sphincter electromyography, and trans-stomic transit examinations showed normal findings, indicating that it was appropriate to proceed with the closure of the colostomy. The postoperative course was uneventful. The optimal management for extraperitoneal penetrating rectal injuries continues to evolve. Primary repair with fecal diversion is the mainstay of treatment, and a conservative approach to rectal lacerations with an internal balloon in a rectal probe could provide a possibility for healing with a lower risk of complications.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.215-223
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• 2022

Objective : This retrospective study investigated the clinical and angiographic characteristics of ruptured true posterior communicating artery (PCoA) aneurysms in comparison with junctional PCoA aneurysms presenting with a subarachnoid hemorrhage. Methods : The medical records and radiological data of 93 consecutive patients who underwent three-dimensional rotational angiography and surgical or endovascular treatment for a ruptured junctional or true PCoA aneurysm over an 8-year period were examined. Results : The maximum diameter of the ruptured true PCoA aneurysm (n=13, 14.0%) was significantly smaller than that of the ruptured junctional PCoA aneurysms (n=80, 4.45±1.44 vs. 7.68±3.36 mm, p=0.001). In particular, the incidence of very small aneurysms <4 mm was 46.2% (six of 13 patients) in the ruptured true PCoA aneurysm group, yet only 2.5% (two of 80 patients) in the ruptured junctional PCoA aneurysm group. Meanwhile, the diameter of the PCoA was significantly larger in the true PCoA aneurysm group than that in the junctional PCoA aneurysm group (1.90±0.57 vs. 1.15±0.49 mm, p<0.001). In addition, the ipsilateral PCoA/P1 ratio was significantly larger in the true PCoA aneurysm group than that in the group of a junctional PCoA aneurysm (mean PCoA/P1 ratio±standard deviation, 2.67±1.22 vs. 1.14±0.88; p<0.001). No between-group difference was identified for the modified Fisher grade, clinical grade at admission, and 3-month modified Rankin Scale score. Conclusion : A true PCoA aneurysm was found to be associated with a larger PCoA and ruptured at a smaller diameter than a junctional PCoA aneurysm. In particular, the incidence of a ruptured aneurysm with a very small diameter <4 mm was significantly higher among the patients with a true PCoA aneurysm.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4253-4264
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• 2022

Since the implementation of the phosphate project in Bled El-Hadba (BEH) deposit, western region of Tébessa, no detailed study has been conducted to assess the natural radioactivity distribution and the associated radiological risk parameter for this open-pit mine. For the sake of determining a credible premining reference database for the region of interest, 21 samples were collected from different geological layers of the above-mentioned deposit. Gamma Spectrometry was applied for measuring radioactivity using a high resolution HPGe semiconductor detector. The obtained activity results have shown a significant broad variation in the radioactive contents for the different phosphate samples. The total average concentrations (in Bq·kg^-1) for ²²⁶Ra, ²³⁸U, ²³⁵U, ²³²Th and ⁴⁰K computed for the different type of phosphate layers were found to be 570 ± 169, 788 ± 280, 52 ± 18, 66 ± 6 and 81 ± 18 respectively. The mean activity concentrations of the measured radionuclides were compared to other regional and worldwide deposits. The ratios between the detected radioisotopes have been calculated for spatial distribution of natural radionuclides in the study area. Based on the aforementioned activity concentrations, the corresponding radiation hazard parameters were assessed. Correlations between the obtained parameters were drawn and a multivariate statistical analysis (Pearson Correlation, Cluster and Factor analysis) was carried out in order to identify the existing relationships.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.1949-1958
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• 2023

The International Commission on Radiological Protection (ICRP) Publication 116 was released to provide a comprehensive dataset of the dose coefficients (DCs) for external exposures produced with the adult reference voxel phantoms of ICRP Publication 110. Although an advanced skeletal dosimetry method for photons and neutrons using fluence-to-dose response functions (DRFs) was introduced in ICRP Publication 116, the ICRP-116 skeletal DCs were calculated by using the simple method conventionally used (i.e., doses to red bone marrow and endosteum approximated by doses to spongiosa and/or medullary cavities). In the present study, the photon and neutron DRFs were used to produce skeletal DCs of the ICRP-110 reference phantoms, which were then compared with the ICRP-116 DCs. For photons, there were significant differences by up to ~2.8 times especially at energies <0.3 MeV. For neutrons, the differences were generally small over the entire energy region (mostly <20%). The general impact of the DRF-based skeletal DCs on the effective dose calculations was negligibly small, supporting the validity of the ICRP-116 effective DCs despite their skeletal DCs derived from the simple method. Meanwhile, we believe that the DRF-based skeletal DCs could be beneficial in better estimates of skeletal doses of individuals for risk assessments.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.459-464
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• 2023

Due to the development of advanced technology, a lot of digital radiographic equipment has been developed, which is very helpful for accurate diagnosis and treatment, and it is very important to train personnel who have acquired professional knowledge in order to use it safely and effectively. Students are exposed to the risk of radiation exposure in radiography training using diagnostic X-ray equipment, and some educational institutions do not use X-ray equipment due to management difficulties in accordance with the Nuclear Safety Act. As a solution to this, this study developed a medical radiation simulator for education that does not generate radiation by using a vision sensor and self-developed software. Through this, educational institutions can reduce the burden of administrative implementation according to the law, and students can obtain a high level of educational effects in a healthy practice environment without radiation exposure.

• Biomedical Science Letters
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• v.29 no.4
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• pp.363-370
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• 2023

Human respiratory viral infections such as COVID-19 are highly contagious, so continuous management of airborne viruses is essential. In particular, indoor air monitoring is necessary because the risk of infection increases in poorly ventilated indoors. However, the current method of detecting airborne viruses requires a lot of time from sample collection to confirmation of results. In this study, we proposed a system that can monitor airborne viruses in real time to solve the deficiency of the present method. Air samples were collected in liquid form through a bio sampler, in which case the virus is present in low concentrations. To detect viruses from low-concentration samples, viral RNA was concentrated and extracted using silica-magnetic beads. RNA binds to silica under certain conditions, and by repeating this binding reaction, bulk samples collected from the air can be concentrated. After concentration and extraction, viral RNA is specifically detected through real-time qPCR (quantitative polymerase chain reaction). In addition, based on liquid handling technology, we have developed an automatic machine that automatically performs the entire testing process and can be easily used even by non-experts. To evaluate the system, we performed air sample collection and automated testing using bacteriophage MS2 as a model virus. As a result, the air-collected samples concentrated by 45 times then initial volume, and the detection sensitivity of PCR also confirmed a corresponding improvement.

• PNF and Movement
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• v.22 no.1
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• pp.43-54
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• 2024

Purpose: Falls among persons older than 65 years are a significant concern due to their frequency and severity. This study aimed to develop a vest-type embedded artificial intelligence (AI) system capable of detecting and predicting falls in various scenarios. Methods: In this study, we established and developed a vest-type embedded AI system to judge and predict falls in various directions and situations. To train the AI, we collected data using acceleration and gyroscope values from a six-axis sensor attached to the seventh cervical and the second sacral vertebrae of the user, considering accurate motion analysis of the human body. The model was constructed using a neural network-based AI prediction algorithm to anticipate the direction of falls using the collected pedestrian data. Results: We focused on developing a lightweight and efficient fall prediction model for integration into an embedded AI algorithm system, ensuring real-time network optimization. Our results showed that the accuracy of fall occurrence and direction prediction using the trained fall prediction model was 89.0% and 78.8%, respectively. Furthermore, the fall occurrence and direction prediction accuracy of the model quantized for embedded porting was 87.0 % and 75.5 %, respectively. Conclusion: The developed fall detection and prediction system, designed as a vest-type with an embedded AI algorithm, offers the potential to provide real-time feedback to pedestrians in clinical settings and proactively prepare for accidents.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.759-770
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• 2022

The importance of ethics in research and the use of artificial intelligence (AI) is increasingly recognized not only in the field of healthcare but throughout society. This article intends to provide domestic readers with practical points regarding the ethical issues of using radiological images for AI research, focusing on data security and privacy protection and the right to data. Therefore, this article refers to related domestic laws and government policies. Data security and privacy protection is a key ethical principle for AI, in which proper de-identification of data is crucial. Sharing healthcare data to develop AI in a way that minimizes business interests is another ethical point to be highlighted. The need for data sharing makes the data security and privacy protection even more important as data sharing increases the risk of data breach.

• Journal of Radiation Protection and Research
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• v.49 no.1
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• pp.50-64
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• 2024

Background: The reference dose coefficients (DCs) of the International Commission on Radiological Protection (ICRP) have been widely used to estimate organ doses of individuals for risk assessments. This approach has been well accepted because individual anatomy data are usually unavailable, although dosimetric uncertainty exists due to the anatomical difference between the reference phantoms and the individuals. We attempted to quantify the individual variation of organ doses for photon external exposures by calculating and comparing organ DCs for 30 individuals against the ICRP reference DCs. Materials and Methods: We acquired computed tomography images from 30 patients in which eight organs (brain, breasts, liver, lungs, skeleton, skin, stomach, and urinary bladder) were segmented using the ImageJ software to create voxel phantoms. The phantoms were implemented into the Monte Carlo N-Particle 6 (MCNP6) code and then irradiated by broad parallel photon beams (10 keV to 10 MeV) at four directions (antero-posterior, postero-anterior, left-lateral, right-lateral) to calculate organ DCs. Results and Discussion: There was significant variation in organ doses due to the difference in anatomy among the individuals, especially in the kilovoltage region (e.g., <100 keV). For example, the red bone marrow doses at 0.01 MeV varied from 3 to 7 orders of the magnitude depending on the irradiation geometry. In contrast, in the megavoltage region (1-10 MeV), the individual variation of the organ doses was found to be negligibly small (differences <10%). It was also interesting to observe that the organ doses of the ICRP reference phantoms showed good agreement with the mean values of the organ doses among the patients in many cases. Conclusion: The results of this study would be informative to improve insights in individual-specific dosimetry. It should be extended to further studies in terms of many different aspects (e.g., other particles such as neutrons, other exposures such as internal exposures, and a larger number of individuals/patients) in the future.