• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.32 no.1
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• pp.9-14
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• 2021

Spasmodic dysphonia, essential tremor, and vocal tremor related with Parkinson's disease are different disorders showing fairly similar symptoms such as difficulty in the speech onset, and tremble in the voice. However, the cause and the resulting treatment of these diseases are different. Spasmodic dysphonia is a vocal disorder characterized by spasms of the laryngeal muscles during a speech, invoking broken, tense, forced, and strangled voice patterns. Such difficult-to-treat dysphonia disease is classified as central-origin-focal dystonia, of a yet unknown etiology. Its symptoms arise because of intermittent and involuntary muscle contractions during speech. Essential tremor, on the other hand, is characterized by a rhythmic laryngeal movement, resulting in alterations of rhythmic pitch and loudness during speech or even at rest. Severe cases of tremor may cause speech breaks like those of adductor spasmodic dysphonia. In the case of hyper-functional tension of vocal folds and accompanying tremors, it is necessary to distinguish these disorders from muscular dysfunction. A diversified assessment through the performance of specific speech tasks and a thorough understanding for the identification of the disorder is necessary for accurate diagnosis and effective treatment of patients with vocal tremors.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.2
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• pp.231-241
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• 2022

Several countries, including Korea, are considering the direct disposal of spent nuclear fuels. The radiological safety assessment results published after a geological repository closure indicate that the instant release is the main radiation source rather than the congruent release. Three Safety Case reports recently published were reviewed and the IRF values of seven long-lived radionuclides, including relevant experimental results, were compared. According to the literature review, the IRF values of both the CANDU and low burnup PWR spent fuel have been experimentally measured and used reasonably. In particular, the IRF values of volatile long-lived nuclides, such as ¹²⁹I and ¹³⁵Cs, were estimated from the FGR value. Because experimental leaching data regarding high burnup spent nuclear fuels are extremely scarce, a mathematical modelling approach proposed by Johnson and McGinnes was successfully applied to the domestic high burnup PWR spent nuclear fuel to derive the IRF values of iodine and cesium. The best estimate of the IRF was 5.5% at a discharge burnup of 55 GWd tHM^-1.

• Journal of Audiology & Otology
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• v.25 no.2
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• pp.89-97
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• 2021

Background and Objectives: Bilateral sequential vestibular neuritis (BSVN) is a rare condition in which an inflammation or an ischemic damage of the vestibular nerve occurs bilaterally in a sequential pattern. We described four cases of BSVN. Subjects and Methods: Every patient underwent video-head impulse test during the first and the second episode of vestibular neuritis (VN), furthermore they have been studied with radiological imaging. Results: Contralateral VN occurred after a variable period from prior event. Vestibular function recovered from the first episode in one case. The other three patients developed contralateral VN. One case was due to a bilateral VN in association with a Ramsay-Hunt syndrome, in another patient clinical records strongly suggested an ischemic etiology, whereas in two cases aetiology remained uncertain. Two patients subsequently developed a benign paroxysmal positional vertigo involving the posterior canal on the side of the latest VN (Lindsay-Hemenway syndrome). Conclusions: Instrumental vestibular assessment represents a pivotal tool to confirm the diagnosis of VN and BSVN.

• Korean Journal of Audiology
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• v.25 no.2
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• pp.89-97
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• 2021

Background and Objectives: Bilateral sequential vestibular neuritis (BSVN) is a rare condition in which an inflammation or an ischemic damage of the vestibular nerve occurs bilaterally in a sequential pattern. We described four cases of BSVN. Subjects and Methods: Every patient underwent video-head impulse test during the first and the second episode of vestibular neuritis (VN), furthermore they have been studied with radiological imaging. Results: Contralateral VN occurred after a variable period from prior event. Vestibular function recovered from the first episode in one case. The other three patients developed contralateral VN. One case was due to a bilateral VN in association with a Ramsay-Hunt syndrome, in another patient clinical records strongly suggested an ischemic etiology, whereas in two cases aetiology remained uncertain. Two patients subsequently developed a benign paroxysmal positional vertigo involving the posterior canal on the side of the latest VN (Lindsay-Hemenway syndrome). Conclusions: Instrumental vestibular assessment represents a pivotal tool to confirm the diagnosis of VN and BSVN.

• Korean Journal of Radiology
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• v.25 no.5
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• pp.459-472
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• 2024

Hyperpolarized (HP) carbon-13 (¹³C) MRI represents an innovative approach for noninvasive, real-time assessment of dynamic metabolic flux, with potential integration into routine clinical MRI. The use of [1-¹³C]pyruvate as a probe and its conversion to [1-¹³C]lactate constitute an extensively explored metabolic pathway. This review comprehensively outlines the establishment of HP ¹³C-MRI, covering multidisciplinary team collaboration, hardware prerequisites, probe preparation, hyperpolarization techniques, imaging acquisition, and data analysis. This article discusses the clinical applications of HP ¹³C-MRI across various anatomical domains, including the brain, heart, skeletal muscle, breast, liver, kidney, pancreas, and prostate. Each section highlights the specific applications and findings pertinent to these regions, emphasizing the potential versatility of HP ¹³C-MRI in diverse clinical contexts. This review serves as a comprehensive update, bridging technical aspects with clinical applications and offering insights into the ongoing advancements in HP ¹³C-MRI.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2732-2739
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• 2024

This study developed internal dose coefficients for radioiodine, tailored to the Korean population, by incorporating the Korean biokinetic model along with the Korean S values. The observed differences in dose coefficients for Koreans compared to the International Commission on Radiological Protection (ICRP) reference values noticeably varied depending on physical half-lives of iodine isotopes. For longer-lived isotopes such as I-125 and I-129, significant differences in thyroid dose coefficients were observed, with ratios (Korean/ICRP) from 0.30 to 0.55, indicating that actual doses for Koreans can be considerably lower than those evaluated based on the ICRP data. However, for short-lived iodine isotopes, such as I-131, the thyroid dose coefficients were comparable to the ICRP reference values (ratio = 0.95-0.98). These comparable dose coefficients resulted from the lower thyroidal iodine uptake in the Korean model being almost entirely offset by the higher thyroid self-absorption S values in the Korean phantoms. Additionally, this study delves into the substantial differences in absorbed dose coefficients for non-thyroidal regions and effective dose coefficients, which arose not only from physiological/anatomical variability but also technical differences in phantom design. The use of Korean-specific dose coefficients is advisable particularly in scenarios predicting elevated doses, yielding a more precise and clinically relevant dose assessment.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.1
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• pp.37-42
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• 2007

Purpose: Because of the anatomical characteristics, it is difficult to perform radical operation in spinal tumor. Numerous operations on primary and metastatic spinal tumor have been performed and among those total en bloc spondylectomy has produced decent clinical result. Clinical and radiological results have been analyzed based on five total en bloc spondylectomy on primary and metastatic spinal tumor. Materials and Methods: Patients included in this study were one with primary and four with metastatic spinal tumors, from June 1997 to January 2006. Two of the four were originated form kidney. One was from breast and the other one was not identified. McAfee's 4 point scale, VAS and Frankel's classification have been used as clinical assessment of pain and neurological symptoms. Clinical assessment have been conducted for every 3 months after operation including local recurrence, bone union and complications. Results: Assessment of pain decreased from average of 3 before operation to 1.6 after operation in McAfee's scale and VAS decreased from average of 9.2 to 1.6. Neurological deficit after operation improved from C to D in Frankel's category. Local recurrence has been detected on metastatic adenocarcinoma of L4 during follow up. Conclusion: Total en bloc spondylectomy is evidently useful operational method for primary and metastatic spinal tumor since it completely decompresses spinal nerves, decreases axial pain immediately and improves the quality of remaining life.

• Journal of Radiation Protection and Research
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• v.29 no.2
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• pp.129-139
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• 2004

Recently, much attentions are paid to the risk associated with increased uses of medium size radiation sources in medical and industrial fields. In this study, radiation risks to the worker and to the general public due to $^{99m}Tc$ generator were assessed for both normal and accident conditions. Based on the event tree technique, exposure scenarios for various situations were derived. Uncertainty analysis based on the Monte-Carlo technique was applied to the risk assessment for workers and members of the public in the vicinity of the work place. In addition, sensitivity analysis was performed on each of the five independent input parameters to identify importance of the parameters with respect to the resulting risk. Because the frequencies of normal tasks are fat higher than those of accidents, the total risk associated with normal tasks were higher than the accident risk. The annual dose due to normal tasks were $0.6mSv\;y^{-1}$ for workers and $0.014mSv\;y^{-1}$ for public, while in accident conditions $3.96mSv\;y^{-1}\;and\;0.0016mSv\;y^{-1}$, respectively. Uncertainty range of accident risk was higher by 10 times than that of normal risk. Sensitivity analysis revealed that source strength, working distance and working time were crucial factors affecting risk. This risk analysis methodology and its results will contribute to establishment of risk-informed regulation for medium and large radioactive sources.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.150-169
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• 2023

Multiple myeloma (MM) is a malignant hematologic disease caused by the proliferation of clonal plasma cells in the bone marrow, and its incidence is increasing in Korea. With the development of treatments for MM, the need for early diagnosis and treatment has emerged. In recent years, the International Myeloma Working Group (IMWG) has been constantly revising the laboratory and radiological diagnostic criteria for MM. In addition, as whole-body MRI (WBMR) has been increasing used in the diagnosis and treatment response evaluation of patients with MM, the Myeloma Response Assessment and Diagnosis System (MY-RADS) was created to standardize WBMR image acquisition techniques, image interpretation, and response evaluation methods. Radiologists need to have a detailed knowledge of the features of MM for accurate diagnosis. Thus, in this review article, we describe the imaging method for MM according to the latest IMWG guidelines as well as the image acquisition and response evaluation technique for WBMR according to MY-RADS.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.325-334
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• 2009

Purpose : This study was conducted to assess how effective the permeability ratio and relative cerebral blood volume ratio are to tumor through perfusion MRI by measuring and reflecting the grade assessment and differential diagnosis and the permeability and relative cerebral blood volume of contrast media plunged from blood vessel into organ due to breakdown of blood-brain barrier in cerebral. Subject and Method : Subject of study was 29 patients whose diagnosis were confirmed by biopsy after surgery and 550 (11 slice$\times$50 image) perfusion MRI were used to make image of relative cerebral blood volume with the program furnished on instrument. The other method was to transmit to private computer and the image analysis was made additionally by making image of relative cerebral blood volume-reformulated singular value decomposition, rCBV-rSVD and permeability using IDL.6.2. In addition, Kruskal-wallis test tonggyein non numerical average by a comparative analysis of brain tumors Results : The rCBV ratio (Functool PF; GE Medical Systems and IDL 6.2 program by analysis) and permeability ratio of tumors were as follows; high grade glioma(n=4), (14.75, 19.25) 13.13. low grade astrocytoma(n=5) (14.80, 15.90) 11.60, glioblastoma(n=5) (10.90, 18.60), 22.00, metastasis(n=6) (11.00, 15.08). 22.33. meningioma(n=6) (18.58, 7.67), 5.58. oliogodendroglioma(n=3) (23.33, 16.33, 15.67. Conclusion : It was not easy to classify the grade with the relative cerebral blood volume ratio measured by using the relative cerebral blood image by type of tumors, however, permeability ratio measured by permeability image revealed that the higher the grade of tumor, the higher the measured permeability ratio, showing the assessment of tumor grade is more effective to differential diagnosis.