• Progress in Medical Physics
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• v.28 no.4
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• pp.190-196
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• 2017

For the $ViewRay^{(R)}$ system (ViewRay Inc., Cleveland, OH, USA) which is representative of magnetic resonance (MR) guided radiotherapy machine, it is important to evaluate effectiveness of AAPM's TG-51 protocol and the effect of the magnetic field on absolute dosimetry. In order to measure the absolute dose, MR-compatible chamber and water phantom system manufactured in this study were used. The materials of the water phantom system were plastic of polymethyl methacrylate (PMMA) and non-ferrous materials. Due to the inherent feature of the $ViewRay^{(R)}$, all Co-60 sources are not located at gantry angle of $0^{\circ}$ while being located at gantry angle of $90^{\circ}$. For this reason, absolute dosimetry was performed based on the measurements in solid water phantom (SWP) and water which determine the SWP to water correction factor. For evaluation of output constancy with gantry angle, measurements were made with ionization chamber inserted in cylindrical water-equivalent phantom. For measured doses in water, the values of dose deviation according to a reference dose of 200 cGy for Head 1, Head 2 and Head 3 were -0.27%, -0.45% and -0.22%, respectively. For measured doses in SWP, the values of dose deviation according to a reference dose of 200 cGy for Head 1, Head 2 and Head 3 were -1.91%, -2.07% and -1.84%, respectively. All values of dose measured in SWP tended to be less than those measured in water by -1.63%. With the reference gantry angles of $0^{\circ}$ and $90^{\circ}$, the maximum values of deviation for Head 1, Head 2 and Head 3 were 0.48%, 1.06% and 0.40%, respectively. The measurement agreement is within the range of results obtainable for conventional treatment machines. The low strength of the magnetic field does not affect dose measurements. Using the SWP to water correction factor, absolute doses for $ViewRay^{(R)}$ system can be measured.

• Journal of the Korean Magnetics Society
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• v.24 no.6
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• pp.191-196
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• 2014

The purpose of this study is to evaluate the reproducibility and usefulness of an image through the fusion of the computed tomography image and the magnetic resonance image by using a self-produced phantom when planning the treatment, and also to compare and analyze the target dose on the acquired image. The size of small hole and the reproducibility of capacity existed in the phantom on the image of the phantom obtained by the computed tomography and the magnetic resonance image of the phantom scanning with different intensity of magnetic field are compared, and the change of dose in the random target is compared and analyzed.

• The Korean Journal of Pain
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• v.36 no.4
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• pp.408-424
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• 2023

Central post-stroke pain (CPSP) is an incapacitating disorder that impacts a substantial proportion of stroke survivors and can diminish their quality of life. Conventional therapies for CPSP, including tricyclic antidepressants, anticonvulsants, and opioids, are frequently ineffective, necessitating the investigation of alternative therapeutic strategies. Repetitive transcranial magnetic stimulation (rTMS) is now recognized as a promising noninvasive pain management method for CPSP. rTMS modulates neural activity through the administration of magnetic pulses to specific cortical regions. Trials analyzing the effects of rTMS on CPSP have generated various outcomes, but the evidence suggests possible analgesic benefits. In CPSP and other neuropathic pain conditions, high-frequency rTMS targeting the primary motor cortex (M1) with figure-eight coils has demonstrated significant pain alleviation. Due to its associaton with analgesic benefits, M1 is the most frequently targeted area. The duration and frequency of rTMS sessions, as well as the stimulation intensity, have been studied in an effort to optimize treatment outcomes. The short-term pain relief effects of rTMS have been observed, but the long-term effects (> 3 months) require further investigation. Aspects such as stimulation frequency, location, and treatment period can influence the efficacy of rTMS and ought to be considered while planning the procedure. Standardized guidelines for using rTMS in CPSP would optimize therapy protocols and improve patient outcomes. This review article provides an up-to-date overview of the incidence, clinical characteristics, outcome of rTMS in CPSP patients, and future perspective in the field.

• Journal of the Korean Ceramic Society
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• v.33 no.1
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• pp.119-125
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• 1996

Magnetic properties through controlled nucleation and crystallization wer studied for ferrimagnetic 40Fe2O3-20CaO-40SiO2 glass useful as thermoseeds for hyperthermia of tumor therapy. The maximum nucleation and crystal growth temperature are $700^{\circ}C$ and 100$0^{\circ}C$ respectively. The glass showed the maximum saturation magnetization of 168.4 emu/cm3 when nucleated $700^{\circ}C$ for 60 min and crystal grown at 100$0^{\circ}C$ for 4hrs. The maximum coercive force was 390 Oe when uncleated $700^{\circ}C$ for 60 min and crystal grown at 975$^{\circ}C$ for 2 hrs. The variation of the saturation magnetization could be well quantitatively interpreted in terms of the volume fraction of the magnetite whereas that of the coercive forces could be explained only qual.itatively in terms of the particle size of the magnetite. Hysteresis losses showed the maximum value of 0.18W/cm3 when heat treated at 100$0^{\circ}C$ for 4 hrs pre-necleated at $700^{\circ}C$ for 60 min and temperature increase of 7K under AC magnetic field of 10 kOe and 10kHz.

• Journal of radiological science and technology
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• v.43 no.1
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• pp.35-43
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• 2020

The purpose of this study was to study on radiologic technologist's license system and primary pathway education curriculum in the United States American (USA), focused on one case of college in Texas. We were collected and analyzed through class participation at a community college in Tarrant, interviews with professors of radiologic science and clinical radiographers, field trips, an internet search, and literature reviews. As a result, first, the American radiologic technologists license system is composed of fifteen chapters, and the professional education courses for each field are being carried out through three courses of a primary pathway, a post primary pathway and a physician extender. Second, the primary pathway courses consisted the radiography, the radiation therapy, the nuclear medicine, the magnetic resonance imaging, the sonography. Third, the USA had about 30 times more clinical practice time than Korea. In clinical practice, students had done actually examination through X-ray exposure on patients. Last radiographers in the USA was able to perform intravenous injection of radiopharmaceutical agents on patient, so that he could perform rapid examination and efficient manpower operation. This study could be used as basic data for the globalization of radiologic technologists license system in Korea.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.2
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• pp.34-43
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• 2002

In this paper, with the reference of the pulse wave acquired by the pulse-checking device, it is measured the impedance on the key measuring points of the 12 kyungmaks of the human body's left and right by using 24-channels Yangdorak machine. Then, based on the Fuzzy theory, this study diagnosed the each meridian's strength and weakness. After that, both the strengthening and weakening stimulus of magnetic fields are applied to the dominant direction to find out how the degree of strength and weakness of the meridian changed. Ultimately, the magnetic therapy that can stimulate the magnetic field at the time of diagnosis and thereby balancing the interactive of five-system(O-hang) have been materialized. For the stimulation of magnetic fields, a stimulating device which can change the direction and time on a specific part of the key measuring points of the limbs of 24 kyungmaks have been developed and used. The therapeutic methods are as follows. First, the strength and weakness of the meridian have been determined. Second, both the extremely weak meridian of Yin(Shade) and Yang(Shine), and the extremely strong meridian of Yin and Yang were adjusted by applying appropriate ascending and descending stimuli respectively. All these adjusting processes can now be carried out automatically on a personal computer(PC). 

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.352-359
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• 2020

Inorganic nanoparticles have been actively applied to the bio-medical field by utilizing their physical properties derived from the nanometer size regime, such as optical and magnetic properties. In recent years, diagnostic detection methods have been developed by employing chemical activity, particularly enzyme-mimetic activities, as well as physical properties of inorganic nanoparticles. After the initial study of verifying the enzyme-mimetic activities, the scope of research has been expanded to the direct use of therapeutic effects with active control of activity through understanding of the catalytic mechanism. This review summarizes recent research works on the active control of the enzyme-mimetic activities and newly demonstrated applications on the diagnosis and treatment of diseases, focusing on inorganic nanoparticles, so-called "nanozyme". It is expected that the enzyme-mimetic activity of inorganic nanoparticles will be combined with their inherent physical properties, leading to the development of new diagnostic and therapeutic methods.

• Polymer(Korea)
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• v.30 no.6
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• pp.572-575
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• 2006

In this work, a variety of polymer based jelly phantoms suitable for the hyperthermia operations to human organs was synthesized in order to confirm the possibility of auxiliary cancer therapy. Specifically, using an appropriate material composition including polyethylene, Jelly phantoms for brain was prepared and characterized their electrical properties suitable for the monitoring the effect of electromagnetic wave from code division multiple access (CDMA) and personal communication service (PCS) on the human body. In the future, after injection of ferromagnetic nanoparticle into the jelly phantoms, new approach to propose the cancer therapy can be anticipated by monitoring the degree of temperature rise in human body using the photograph of Infrared camera.

• Journal of Korean Neurosurgical Society
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• v.48 no.1
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• pp.59-61
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• 2010

Neurocysticercosis is the most common parasitic disease of the central nervous system in humans, caused by infection of the larval stage of the pork tapeworm, Taenia solium. However, cerebellar involvement is rarely reported. We report of a case of racemose cysticercosis in the cerebellar hemisphere. A 44-year-old man presented with headache and dizziness. Magnetic resonance imaging showed hydrocephalus and an ill-defined, multicystic cerebellar mass with hypersignal on T2-weighted images, hyposignal on T1-weighted images and rim enhancement after gadolinium injection. The patient underwent endoscopic third ventriculostomy and the cyst resection was done through a craniotomy. In surgical field, cysts were conglomerated in a dense collagen capsule that were severely adherent to surrounding cerebellar tissue, and transparent cysts contained white, milky fluid. Histological findings confirmed the diagnosis of cysticercosis. He received antiparasitic therapy with praziquantel after surgery. Racemose cysticercosis is rare in the cerebellar hemisphere but neurocysticercosis should be taken into consideration as a differential diagnosis of multiple cystic lesions in the cerebellum.

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.111-114
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• 2004

Molecular imaging provides a visualization of normal as well as abnormal cellular processes at a molecular or genetic level rather than at a anatomical level. Conventional medical imaging methods utilize the imaging signals produced by nonspecific physico-chemical interaction. However, molecular imaging methods utilize the imaging signals derived from specific cellular or molecular events. Because molecular and genetic changes precede anatomical change in the course of disease development, molecular imaging can detect early events in disease progression. in the near future, through molecular imaging we can understand basic mechanisms of disease, and diagnose earlier and, subsequently, treat earlier intractable diseases such as cancer, neuro-degenerative diseases, and immunologic disorders. In beginning period, nuclear medicine started as a molecular imaging, and has had a leading role in the field of molecular imaging. But recently molecular imaging has been rapidly developed. Besides nuclear imaging, molecular imaging methods such as optical imaging, magnetic resonance imaging are emerging. Each imaging modalities have their advantages and weaknesses. The opportunities from molecular imaging look bright. We should try nuclear medicine continues to have a leading role in molecular imaging.