• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.383-387
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• 2014

In this paper, for a new detection system development with the better accurate dose evaluation and beam distribution imaging using the small field irradiation of linear accelerator, the compound semiconductor based detection sensors were fabricated and the performance evaluation was investigated. The special particle-in-binder sedimentation was used for a large area film sensor fabrication. The detection properties for high energy x-rays were investigated from a dark current, an output current, a rising time, a falling time, and response delay measurement. The experimental results, the $TiO_2$ mixed $HgI_2$ sensor showed the best electrical characteristics than $PbI_2$, PbO, pure $HgI_2$. Linearity, repeatability, and accuracy tests from LINAC were tested, the $TiO_2$ mixed $HgI_2$ sensor showed the better performance than the commercially available dosimetry devices.

• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.221-225
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• 2017

To evaluate the performance of ultrasound imaging system, we investigated the change of spatial resolution according to changing sonic velocity change parameter provided by ultrasound equipment. Ultrasound phantom images were obtained using a 3.0 ~ 5.0 MHz convex transducer in an ultrasound diagnostic device used at a medical institution located at Iksan. N-365 multi-purpose ultrasound phantom was used to measure longitudinal distance measurement accuracy and longitudinal and transverse resolution. In the same manner, the sonic velocity of the ultrasound equipment was changed from 1580 m/sec to 1400 m/sec in six steps, and the full width at half maximum(FWHM) was measured using the image J program to determine whether the measured values were different. As a result, lateral resolution was measured from 1.91 mm to 5.3 mm according to the speed change, and the smallest FWHM was 1.91 mm at 1420 m/sec. The axial resolution was measured from 1.03 mm to 1.14 mm according to the speed change, and the smallest FWHM was 1.03 mm at 1400 m/sec. The slower the sound velocity of the ultrasound equipment, the shorter the length of longitudinal measurement.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.619-625
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• 2017

The sudy was intended to evaluate the optimal equipment selection by quantitatively assessing the SNR(signal to noise ratio) and CNR(contrast to noise ratio) on the abdominal organ. This study performed on 1.5 T and 3.0 T MRI units focusing on HASTE, HASTE(f/s) and FFE(in of phase), FFE(out of phase) without using the contrast medium(Gadolinium). The data analysis was performed by randomly selecting on 1.5 T and 3.0 T abdominal MRI images. As a results, SNR and CNR values of 3.0 T is higher than 1.5 T at liver, kidney and spleen(p<0.05). Stomach, abdominal fat and pancreas was obtained a higher value at 1.5 T(p<0.05). On conclusion, the organs of outer part in the body showed generally a high value at 3.0 T, and the organs of inner part in the body including the gas showed a high value at 3.0 T because of a large difference on magnetic susceptibility.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1740-1748
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• 2014

In this paper, we propose an RBAC based personalized health care service platform in order to provide smart management of personal health record using smart devices. It helps to guide healthful service and provide useful information according to one's individual health record. Personalized health care services platform supports a healthy lifestyle by measuring personal health information in a hospital clinical, imaging, and drug data, as well as that can be obtained from smart devices. Everyone can enter his health related data in everyday life such as food, sleeping time, mood, movement and exercise so that one can manage his personal health information of modern smart features. In addition, if necessary, personal health information can be provided to the hospital information system and staff with the consent of the individual. It can be contributed to simplify the complex process for remote medical. The proposed platform, which applies role based access control model to protect security and privacy, supports a smart health care services for users by providing personalized health care services through the smart applications.

• Korean Journal of Acupuncture
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• v.21 no.3
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• pp.21-38
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• 2004

Objectives : Moxibustion has been become very useful tool to prevent and treat various diseases with acupuncture in oriental medicine. Expecially, moxibustion combining the heat stimulation and chemical stimulation of Artemisiae Argyi has a non-invasive characteristics comparing to the other therapeutic tools. However, because the moxibustion makes the patient's skin be burn by the combustible feature of moxibustion, most of people have been scared of being scald. Methods : In this study, we have developed new non-combustible moxibustion tools in collaboration with company (Hana Medical, co. and ICURE, co.) and tested the efficacy through effects of moxibustion of Cheon-chu $(ST_{25})$ on the abdominal thermography of health subject. The non-combustible moxibustion has main characteristics of controlled heating to inhibit being scald and heat stimulation lasting over 1 hrs. Also, to induce the chemical stimulation, the bottom contacting with skin was coated by the extract of artemisiae argyi. The volunteers who participating in this study had taken rest for 20 - 30 mins in room temperature $(23-25^{\circ}C)$ before the examination and informed them what to prohibit smoking, drinking and administration of drug for the previous day The thermography of abdomen including a below part of the chest was taken using Infra-Red Imaging System (IR 2000, MEDI-CORE Co., Korea) by time interval of 15 minutes. Results : The results showed that moxibustion of Cheon-chu $(ST_{25})$ had more potencies of changes on all the ROIs of abdominal thermography than those of control group. Also, it was observed that the quantities of thermal changes following moxibustion of Cheon-chu $(ST_{25})$ been increased significantly comparing that of control group at all the ROIs (region of interest). Observed the thermography classified by ROI, however, moxibustion of Cheon-chu $(ST_{25})$ could modulate ipsilateral specific areas concerning to the abdominal pathway of Stomach Meridian. Conclusion : These results suggest that new non-combustible moxibusion has some similarity as like as the conventional moxibustion and moxibustion of Cheon-chu $(ST_{25})$ may modulate thermal changes of abdominal areas.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.245-250
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• 2011

Parallel imaging technique can provide several advantages for a multitude of MRI applications. Especially, in SENSE technique, sensitivity maps were always required in order to determine the reconstruction matrix, therefore, a number of difference approaches using sensitivity information from coils have been demonstrated to improve of image quality. Moreover, many filtering methods were proposed such as adaptive matched filter and nonlinear diffusion technique to optimize the suppression of background noise and to improve of image quality. In this study, we performed SENSE reconstruction using computer simulations to confirm the most suitable method for the feasibility of filtering effect and according to changing order of polynomial fit that were applied on variation of spatial resolution of sensitivity map. The image was obtained at 0.32T(Magfinder II, Genpia, Korea) MRI system using spin-echo pulse sequence(TR/TE = 500/20 ms, FOV = 300 mm, matrix = $128{\times}128$, thickness = 8 mm). For the simulation, obtained image was multiplied with four linear-array coil sensitivities which were formed of 2D-gaussian distribution and the image was complex white gaussian noise was added. Image processing was separated to apply two methods which were polynomial fitting and filtering according to spatial resolution of sensitivity map and each coil image was subsampled corresponding to reduction factor(r-factor) of 2 and 4. The results were compared to mean value of geomety factor(g-factor) and artifact power(AP) according to r-factor 2 and 4. Our results were represented while changing of spatial resolution of sensitivity map and r-factor, polynomial fit methods were represented the better results compared with general filtering methods. Although our result had limitation of computer simulation study instead of applying to experiment and coil geometric array such as linear, our method may be useful for determination of optimal sensitivity map in a linear coil array.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.5
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• pp.544-555
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• 2002

The aim of this study is to develop the $^1H$-MRS data postprocessing software for both single-voxel and multi-voxel technique, which plays and important role as a diagnostic tool in clinical field. This software is based on graphical user interface(GUI) under windows operating system of personal computer(PC). In case of single-voxel MRS, both of raw data in time-domain and spectrum data in frequency-domain are simultaneously displayed in a screen. Several functions such as DC correction, zero filling, line broadening, Lorentz-Gauss filtering and phase correction, etc. are included to increase the quality of spectrum data. In case of multi-voxel analysis, spectroscopic image reconstructed by 3-D FFT was displayed as a spectral grid and overlapped over previously obtained T1- or T2-weighted image for the spectra to be spatially registered with the image. The analysis of MRS peaks were performed by obtaining the ratio of peak area. In single-voxel method, statistically processed peak-area ratios of MRS data obtained from normal human brain are presented. Using multi-voxel method, MR spectroscopic image and metabolite image acquired from brain tumor are demonstrated.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.89-95
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• 1998

Purpose : To investigate the phosphorus metabolic abnormalities in skeletal muscle of patients with mitochondrial myopathy using in vivo $^{31}P$ magnetic resonance spectroscopy(MRS). Materials and Methods : Patients with mitochondrial myopathy(N=10) and normal control subjects (N=10) participated. All in vivo $^{31}P$ MRS examinations were performed on 1.5T whole-body MRI/MRS system by using an image selected in vivo spectroscopy (ISIS) pulse sequence that provided a $4{\times}4{\times}4{\;}cm^{3}$ volume of interest (VOI) in the right thigh muscle tissue. Peak areas for each phophorus methabolite were measured using a Marquart algorithm. Results : The specific features in patients with mitochondrial myopathy were a significant increase of Pi/PCr ratio (p=0.003) and a significant decrease of ATP/PCr ratio (p=0.004) as compared with normal controls. In particular, the ${\beta}-ATP/PCr$ ratio between controls and patients with mitochondrial myopathy was predominantly altered. Conclusions : In vivo $^{31}P$ MRS may be a useful modality in the clinical evaluation of patients with mitochondrial myopathy based on ATP/PCr and Pi/PCr ratios in skeletal muscle tissue and provides a valuable information in further understanding disorders of muscle metabolism.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.325-332
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• 2018

Carotid angiography covering the aortic arch includes contrast-enhanced magnetic resonance angiography (CEA), which is applied to a large region and usually employs contrast media. However, the use of contrast media can be dangerous in infants, pregnant women, and patients with chronic renal failure (CRF). Follow-up patients informed of a lesion may also want to avoid constant exposure to contrast media. We aimed to apply time-of-flight (TOF) angiography to a large region and compare its usefulness with that of CEA. Ten patients (mean age, 58 years; range, 45~75 years) who visited our hospital for magnetic resonance angiography (MRA) participated in this study. A 3.0 Tesla Achieva magnetic resonance imaging (MRI) system (Philips, Netherland) and the SENSE NeuroVascular 16-channel coil were employed for both methods. Both methods were applied simultaneously to the same patient. Three TOF stacks were connected to cover the aortic arch through the circle of Willis, and CEA was applied in the same manner. For the quantitative assessment, the acquired images were used to set the regions of interest (ROIs) in the common carotid artery (CCA) bifurcation, internal carotid artery, external carotid artery, middle cerebral artery, and vertebral artery, and to obtain the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) for the soft tissues. Three radiologists and one radiological resident performed the qualitative assessment on a 5-point scale - 1 point, "very bad"; 2 points, "bad"; 3 points, "average"; 4 points, "good"; and 5 points, "very good" - with regard to 4 items: (1) sharpness, (2) distortion, (3) vein contamination, and (4) expression of peripheral vessels. For the quantitative assessment, we estimated the mean SNR and CNR in each of the 5 ROIs. In general, the mean SNR was higher in TOF angiography (166.1, 205.2, 154.39, 172.23, and 161.95) than in CEA(92.05, 95.43, 84.76, 73.69, and 88.3). Both methods had a similar mean CNR: 67.62, 106.71, 55.9, 73.74, and 63.46 for TOF angiography, and 67.82, 71.19, 60.52, 49.45, and 64.07 for CEA. In all ROIs, the mean SNR was statistically significant (p<0.05), whereas the mean CNR was insignificant (p>0.05). The mean values of TOF angiography and CEA for each item in the qualitative assessment were 4.2 and 4.28, respectively for item 1; 2.93 and 4.55, respectively, for item 2; 4.6 and 3.13, respectively, for item 3; and 2.88 and 4.65, respectively, for item 4. Therefore, TOF angiography had a higher mean for item 3, and CEA had a higher mean for items 2 and 4; there was no significant difference between the two methods for item 1. The results for item 1 were statistically insignificant (p>0.05), whereas the results for items 2~4 were statistically significant (p<0.05). Both methods have advantages and disadvantages and they complement each other. However, CEA is usually applied to a large region covering the aortic arch. Time-of-flight angiography may be useful for people such as infants, pregnant women, CRF patients, and followup patients for whom the use of contrast media can be dangerous or unnecessary, depending on the circumstance.

• Journal of Ginseng Research
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• v.43 no.2
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• pp.272-281
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• 2019

Background: Diabetic sensorineural damage is a complication of the sensory neural system, resulting from long-term hyperglycemia. Red ginseng (RG) has shown efficacy for treatment of various diseases, including diabetes mellitus; however, there is little research about its benefit for treating sensorineural damage. Therefore, we aim to evaluate RG efficacy in alloxan-induced diabetic neuromast (AIDN) zebrafish. Methods: In this study, we developed and validated an AIDN zebrafish model. To assess RG effectiveness, we observed morphological changes in live neuromast zebrafish. Also, zebrafish has been observed to have an ultrastructure of hair-cell cilia under scanning electron microscopy. Thus, we recorded these physiological traits to assess hair cell function. Finally, we confirmed that RG promoted neuromast recovery via nerve growth factor signaling pathway markers. Results: First, we established an AIDN zebrafish model. Using this model, we showed via live neuromast imaging that RG fostered recovery of sensorineural damage. Damaged hair cell cilia were recovered in AIDN zebrafish. Furthermore, RG rescued damaged hair cell function through cell membrane ion balance. Conclusion: Our data suggest that RG potentially facilitates recovery in AIDN zebrafish, and its mechanism seems to be promotion of the nerve growth factor pathway through increased expression of topomyosin receptor kinase A, transient receptor potential channel vanilloid subfamily type 1, and mitogen-activated protein kinase phosphorylation.