Radiological Sciences Research Articles

Nuclear responses of WCCB TBM with different container designs

Abstract In test blanket module (TBM) program blanket major functions, which are tritium production, heat extraction for electric power production, and neutron shielding, will be demonstrated under fusion reactor environments in ITER. National Institutes for Quantum and Radiological Science and Technology (QST) has performed developments of water cooled ceramic breeder (WCCB) TBM as a primary concept in Japan. The container design of WCCB TBM was changed from the Box-shaped to a cylindrical structure to increase tritium breeding capability while maintaining pressure resistance under In-Box LOCA caused by water ingress into the container. The nuclear responses related to the blanket major functions would be changed with the container design change. The nuclear responses of WCCB TBM with the container design change were evaluated and the effects of the changed nuclear responses were described in this study. Tritium production rate increased by about 2 times with the container design changes. In contrast neutron shielding performance decreased due to the container design change. Degradation of neutron shielding in the cylindrical TBM led to an increase in nuclear heating of the TBM frame as well as an average of neuron flux behind TBM-set.

Compact Integration and RF Commissioning of the C-Band 9-MeV Electron Linear Accelerator at the Dongnam Institute of Radiological & Medical Sciences

The 6-MeV C-band standing-wave accelerator was constructed in 2015 and is providing for the beam service. The new 9-MeV accelerator was designed and constructed in 2018 at the Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, Korea. The 5712 MHz accelerating column was designed with an average accelerating gradient of 16.7 MV/m at a pulsed resonance frequency (RF) power of 2.5 MW. The C-band coaxial magnetron was chosen for its high RF power of 2.5 MW and RF frequency of 5712 ± 10 MHz. While the 6-MeV accelerator was operating using a magnetron manufactured by BVERI, China, the 9-MeV accelerator uses a magnetron manufactured by CPI, USA. Though the CPI magnetron requires more heating power and precise heating control for high repetition operation, the frequency spectrum and the RF power distribution are satisfactory for our accelerating columns. The magnetron installed on the 9-MeV accelerator was tested with the 6-MW pulse modulator based on the thyratron-switched pulse-forming network and is currently operating for accelerator RF conditioning. In this paper, we present a brief description of the 9-MeV accelerator, the integration of the RF transport systems and the commissioning status. We also discuss the results obtained during the early commissioning and future plan.

Fabrication and Cold Test of a 9-MeV C-Band Accelerating Column

A 9-MeV electron linear accelerator based on C-band microwaves for medical applications is being assembled at the Dongnam Institute of Radiological and Medical Sciences (DIRAMS). The accelerating column has an on-axis coupled structure and will be operated with a π/2-mode standing wave. Parameters of the cavities are selected based on simulations with CST MICROWAVE STUDIO® (CST MWS), and the cold test and micro-machining are performed to obtain the desired RF characteristics of the cavity. Then, the bead-pull test is conducted to measure the RF properties of the full accelerating column structure. The fabrication of the C-band accelerating column and the results of the low-power RF tests are discussed.

Monte Carlo Simulation of an Electron Irradiation Device for Medical Application of an Electron Linear Accelerator

A uniform electron field is required for medical applications of electron linear accelerators (LINACs). Electron irradiation devices, including scattering foils and applicators for generating uniform electron fields, are widely used in medical LINACs. In this research, an electron scattering device consisting of scattering foils and applicators was designed for clinical application of a 9-MeV electron LINAC planned at the Dongnam Institute of Radiological & Medical Sciences. Monte Carlo simulations were performed to calculate the depth dose and the beam profile curves in a water phantom by using the EGSnrc Monte Carlo code.

방사선학에서의 계수통계에 대한 이해

방사선 계측학에서 계수통계 관련 개념들에 대해 이해하기 위해서는 기본적인 통계지식과 함께 용어 및 개념에 대한 내용을 정확하게 설명하는 연구나 교재가 있어야 하는데, 현재까지 국내에서 발간된 대학교재들은 미흡한 부분이 많다. 이에 본 연구에서는 통계적인 관점에서 계수통계의 이해에 우선적으로 필요한 기초적인 통계지식들에 대하여 정리하고, 오차의 전파 등 계수통계의 주요 내용에 대한 정확한 개념을 소개하였다, 나아가 현재 사용되고 있는 국내 방사선 계측학 관련 대학교재들에서 적절하게 표현되지 못한 부분 및 추가되어야 할 사항 등에 대해서 지적 및 수정권고를 하였다. 본 연구는 통계적 지식이 부족한 상태에서 작성된 일부 교재들로 인하여 계수통계 관련 내용들이 잘못 전달되는 문제점 해소 및 관련 연구의 활성화에 기여할 것으로 사료된다.

Educational Effects of Self-directed Learning Method Using 3D Printing Products on Radiological Science Students

Educational Effects of Self-directed Learning Method Using 3D Printing Products on Radiological Science Students

Invited Commentary on "Optimizing Diffusion-Tensor Imaging Acquisition for Spinal Cord Assessment," with Response from Dr Martín Noguerol et al.

Invited Commentary on "Optimizing Diffusion-Tensor Imaging Acquisition for Spinal Cord Assessment," with Response from Dr Martín Noguerol et al.

Experimental study on monitoring system of clinical beam purity in multiple-ion beam operation for heavy-ion radiotherapy.

The National Institute of Radiological Sciences has investigated multiple-ion therapy using energetic beams of helium, carbon, oxygen, and neon ions, to improve treatment outcomes of refractory cancer. For this therapy, it is necessary to ensure the helium-ion beam purity to avoid irradiation by unwanted ions. Here, we develop a measurement method for monitoring beam purity. This method can measure the charge number of the ions in a high-purity beam using an ionization chamber and Faraday cup. In addition, it can be used to detect the contamination of the clinical helium-ion beam. We perform beam experiments to evaluate our beam-purity monitoring method and predict that our method is capable of detecting contamination below 1%.

Experimental validation of stochastic microdosimetric kinetic model for multi-ion therapy treatment planning with helium-, carbon-, oxygen-, and neon-ion beams

The National Institute of Radiological Sciences (NIRS) has initiated a development project for hypo-fractionated multi-ion therapy. In the treatment, heavy ions up to neon ions will be used as a primary beam, which is a high linear energy transfer (LET) radiation. The fractionated dose of the treatment will be 10 Gy or more. The microdosimetric kinetic (MK) model overestimates the biological effectiveness of high-LET and high-dose radiations. To address this issue, the stochastic microdosimetric kinetic (SMK) model has been developed as an extension of the MK model. By taking the stochastic nature of domain-specific and cell nucleus-specific energies into account, the SMK model could estimate the biological effectiveness of radiations with wide LET and dose ranges. Previously, the accuracy of the SMK model was examined by comparison of estimated and reported survival fractions of human cells exposed to pristine helium-, carbon-, and neon-ion beams. In this study, we verified the SMK model in treatment planning of scanned helium-, carbon-, oxygen-, and neon-ion beams as well as their combinations through the irradiations of human undifferentiated carcinoma and human pancreatic cancer cells. Treatment plans were made with the ion-species beams to achieve a uniform 10% survival of the cells within a cuboid target. The planned survival fractions were reasonably reproduced by the measured survival fractions in the whole region from the plateau to the fragment tail for all planned irradiations. The SMK model offers the accuracy and simplicity required in hypo-fractionated multi-ion therapy treatment planning.

Measurements of production cross-sections of medical radioisotopes (57Ni, 55,57,58Co, 54Mn, 51Cr) and other by-products (56Ni, 56Co, 56Mn) from the 59Co(p,x) reactions

We studied the excitation functions of 59Co(p,x) reactions and measured the production cross-sections of medical radioisotopes (57Ni, 55,57,58Co, 54Mn, 51Cr) and other by-products (56Ni, 56Co, 56Mn) from their threshold to a proton energy of 43.7 MeV. The stacked-foil activation method was employed to irradiate the samples with an external beam from the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS), Korea. Off-line γ-ray spectrometry was used to measure the activities of the produced radionuclides. The integral yields for the thick target of the investigated radionuclides were also calculated from the measured excitation functions. The measured results were compared with the literature data as well as with theoretical values obtained from the TENDL-2017 library based on the TALYS-1.9 code.

ANALYSIS OF MRI UTILIZATION IN PEDIATRIC PATIENTS IN SAUDI ARABIA

13Jan 2020 ANALYSIS OF MRI UTILIZATION IN PEDIATRIC PATIENTS IN SAUDI ARABIA Ali Alghamdi and Majed Alahmari Department of Radiological Sciences, Faculty of Applied Medical Sciences, Tabuk University, Saudi Arabia. Department of Radiology, King Fahad Specialist Hospital, Tabuk, Saudi Arabia.

Artificial Intelligence: reshaping the practice of radiological sciences in the 21st century.

Advances in computing hardware and software platforms have led to the recent resurgence in artificial intelligence (AI) touching almost every aspect of our daily lives by its capability for automating complex tasks or providing superior predictive analytics. AI applications are currently spanning many diverse fields from economics to entertainment, to manufacturing, as well as medicine. Since modern AI's inception decades ago, practitioners in radiological sciences have been pioneering its development and implementation in medicine, particularly in areas related to diagnostic imaging and therapy. In this anniversary article, we embark on a journey to reflect on the learned lessons from past AI's chequered history. We further summarize the current status of AI in radiological sciences, highlighting, with examples, its impressive achievements and effect on re-shaping the practice of medical imaging and radiotherapy in the areas of computer-aided detection, diagnosis, prognosis, and decision support. Moving beyond the commercial hype of AI into reality, we discuss the current challenges to overcome, for AI to achieve its promised hope of providing better precision healthcare for each patient while reducing cost burden on their families and the society at large.

Highlights From the Circulation Family of Journals.

Highlights From the Circulation Family of Journals.

Comparing the Perceptions of Interprofessional Socialization Among Health Profession Students

Introduction: Based on a review of literature, there is a gap of knowledge on how students perceive the professional roles and responsibilities of other disciplines. The purpose of this study was to explore the perceptions of interprofessional socialization among health profession students. Subjects: Participants included 300 undergraduate and 114 graduate students from eight health disciplines: nursing, communication disorders, physical therapy, social work, radiological science, occupational therapy, clinical lab science, and nutritional science. Methods: Data were collected using the Interprofessional Socialization and Valuing Scale (ISVS-21). The participants rated 21 items about their beliefs, behaviors, and attitudes of interprofessional socialization on a Likert scale from 1-7, with 1 being not at all and 7 being to a very great extent. Data were analyzed using descriptive statistics and analysis of variance was conducted to compare the health disciplines for differences. Results: Descriptive analysis revealed that 95.2% of students perceived an awareness of interprofessional socialization as occurring from a fairly great extent to a great extent, with means of 5.12 or higher on the 1-7 scale. There were no significant differences between the health disciplines. Conclusion: Findings suggest that students have the readiness to understand each other’s professional roles and responsibilities. Although there are no standardized educational strategies to facilitate student collaboration between disciplines, considerations for future interprofessional collaborative activities are indicated.

The Future of Radiological Sciences and Artificial Intelligence

The Future of Radiological Sciences and Artificial Intelligence

Measurement of activation cross-sections of natDy(p,x) reactions up to 45 MeV

We activated natDy with a 45-MeV energetic proton beam and studied the production cross-sections of the reaction products 162m,161,159Ho, 159,157,155Dy, and 161,160,156,155Tb. The activation was carried out using an external beam from the MC-50 Cyclotron at the Korea Institute of Radiological and Medical Sciences, Korea. The stacked-foil activation method and off-line γ-ray spectrometry were used to measure the excitation functions of the natDy(p,x) reactions. The thick target yields of the reaction products were also estimated. The excitation functions of the natDy(p,x) reactions were theoretically calculated using TALYS 1.9 code. The measured results were compared with the literature data and the calculated values from the TENDL-2017 library and were found to be in close agreement for most of the reactions.

Comparison of Radon and Thoron Concentration Measuring Systems Among Asian Countries.

Comparison is an important role in the quality control and quality assurance for any measuring system. Due to the future legal regulations regarding radon levels in the air, maintaining the system quality and harmonization of results as well as validation of radon and thoron measuring systems is important. The aim of this work is to validate the degrees of equivalence and measurement precisions of the existing five radon and four thoron measuring systems located in four Asian countries (China, India, Japan and Thailand) through comparison experiment. In this project, comparison experiment was performed in order to derive the ratio between assigned value obtained from one transfer measurement device for radon and one transfer measurement device for thoron belongs to National Institutes for Quantum and Radiological Science and Technology and participants’ value from their measuring instrument. As a result, the ratio value associated with measurement uncertainty was derived for each activity concentration. Finally, measurement bias and degrees of equivalence between the assigned values and values of measurement quantity from participants’ measuring instruments were statistically analysed and presented.

Synchrotron Radiation-Based Techniques Available at QST Advanced Characterization Nanotechnology Platform (National Institutes for Quantum and Radiological Science and Technology)

Synchrotron Radiation-Based Techniques Available at QST Advanced Characterization Nanotechnology Platform (National Institutes for Quantum and Radiological Science and Technology)

Development of Actinium-225 Production Method using Liquid Target

To prepare the radioisotope Ac-225 using the liquid target of the Ra-226 chloride, and to evaluate the durability of the liquid target for this purpose. We will use Barium, a family like Radium. The Ba target was prepared by dissolving BaCl2 in DI water. An amount of 20 g/100 mL was prepared considering the solubility of BaCl2 (35.8 g/100 mL, 20°C) and the amount of 2 mL was loaded on the liquid target. The beam test was carried out using CYCLON 30 Cyclotron (Korea Institute of Radiological & Medical Sciences, IBA, 2001). The target was a large-volume liquid target of IBA and irradiated with energy of 15 - 30 MeV. To optimize irradiation energy and current conditions. To confirm the nuclear transformation, the irradiated target was analyzed using the HPGe detector for γ-spectrum.

Report of the Japan Health Physics Society ad hoc working group for the Plutonium intake accident**An original WG report was published in Jpn J Health Physics, 53(4).271-281 (2018). ‘JHPS Working Group for Plutonium Accident in JAEA-Oarai, Satoshi IWAI, Michiya SASAKI, Shogo HIGAKI, Hirokuni YAMANISHI and Michiaki KAI’ (in Japanese). To share the original report, it has been translated into English

This paper describes an overview of the radiation protection response to the Plutonium intake accident that occurred at the Plutonium Fuel Facility of the Oarai Research and Development Center of the Japan Atomic Energy Agency on 6 June 2017. In the hood of the analyzing room at the Plutonium Fuel Facility five workers were checking a storage container of fast reactor nuclear fuel material. Around 11:15 a.m., vinyl bags inside the fuel material container containing Plutonium and enriched uranium burst during the inspection work. All the workers heard the bang, which caused misty dust leakage from the container. This event caused significant both skin and nasal α-contamination for three workers and just skin α-contamination for one worker. Decontamination was conducted in the shower room. Then the five workers were transferred to the Nuclear Fuel Cycle Engineering Laboratory to evaluate inhalation intake of Plutonium etc in the lungs. The maximum values of 2.2 × 104 Bq for 239Pu and 2.2 × 102 Bq for 241Am were estimated by the lung monitor. Based on these results, injection of a chelate agent was conducted for prompt excretion of Plutonium etc. The next morning, the five workers were transferred to the National Institute of Radiological Sciences for treatment including decontamination of their skin and measurement by a lung monitor. At that time no obvious energy peak was confirmed for Plutonium. The Japan Health Physics Society launched an ad-hoc working group for Plutonium intake accident around the middle of June to survey issues and to extract lessons for radiological protection. The authors, who are the members of the ad-hoc working group, here report the activity of the working group.