• Progress in Medical Physics
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• v.24 no.4
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• pp.237-242
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• 2013

In the intracranial regions, an accurate delineation of the target volume has been difficult with only the CT data due to poor soft tissue contrast of CT images. Therefore, the magnetic resonance images (MRI) for the delineation of the target volumes were widely used. To calculate dose distributions with MRI-based RTP, the electron density (ED) mapping concept from the diagnostic CT images and the pseudo CT concept from the MRI were introduced. In this study, the look up table (LUT) from the fifteen patients' diagnostic brain MRI images was created to verify the feasibility of MRI-based RTP. The dose distributions from the MRI-based calculations were compared to the original CT-based calculation. One MRI set has ED information from LUT (lMRI). Another set was generated with voxel values assigned with a homogeneous density of water (wMRI). A simple plan with a single anterior 6MV one portal was applied to the CT, lMRI, and wMRI. Depending on the patient's target geometry for the 3D conformal plan, 6MV photon beams and from two to five gantry portals were used. The differences of the dose distribution and DVH between the lMRI based and CT-based plan were smaller than the wMRI-based plan. The dose difference of wMRI vs. lMRI was measured as 91 cGy vs. 57 cGy at maximum dose, 74 cGt vs. 42 cGy at mean dose, and 94 cGy vs. 53 at minimum dose. The differences of maximum dose, minimum dose, and mean dose of the wMRI-based plan were lower than the lMRI-based plan, because the air cavity was not calculated in the wMRI-based plan. These results prove the feasibility of the lMRI-based planning for brain tumor radiation therapy.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.171-179
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• 2019

Objective: For localization of the motor cortex, seed-based resting-state functional MRI (rsfMRI) uses the contralateral motor cortex as a seed. However, research has shown that the location of the motor cortex could differ according to anatomical variations. The purpose of this study was to compare the results of rsfMRI using two seeds: a template seed (the anatomically expected location of the contralateral motor cortex) and a functional seed (the actual location of the contralateral motor cortex determined by task-based functional MRI [tbfMRI]). Materials and Methods: Eight patients (4 with glioma, 3 with meningioma, and 1 with arteriovenous malformation) and 9 healthy volunteers participated. For the patients, tbfMRI was performed unilaterally to activate the healthy contralateral motor cortex. The affected ipsilateral motor cortices were mapped with rsfMRI using seed-based and independent component analysis (ICA). In the healthy volunteer group, both motor cortices were mapped with both-hands tbfMRI and rsfMRI. We compared the results between template and functional seeds, and between the seed-based analysis and ICA with visual and quantitative analysis. Results: For the visual analysis, the functional seed showed significantly higher scores compared to the template seed in both the patients (p = 0.002) and healthy volunteers (p < 0.001). Although no significant difference was observed between the functional seed and ICA, the ICA results showed significantly higher scores than the template seed in both the patients (p = 0.01) and healthy volunteers (p = 0.005). In the quantitative analysis, the functional seed exhibited greater similarity to tbfMRI than the template seed and ICA. Conclusion: Using the contralateral motor cortex determined by tbfMRI as a seed could enhance visual delineation of the motor cortex in seed-based rsfMRI.

• Journal of Acupuncture Research
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• v.17 no.3
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• pp.87-98
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• 2000

This study is designed to evaluate the clinical implications of Gd-DPTA (Gadolinium-diethyl enetriamine pentacetic acid) enhanced MRI(Magnetic resonance imaging) in Bell's palsy and find it's usefulness in Oriental Medicine In this study, 25 outparients with Bell's palsy were studied that MRI was performed. To evaluate degree of facial palsy, H-B(House-Brackmann) Grade was used. In Oriental Medical therapy, Acupuncture and Herbal medicine were treated. Subjective cause was divided into exposure to chill, fatigue, stress, mixed cases. Enhanced site was compared with symptoms which were disorder of eye, hearing, taste, and facial muscle palsy. Also, Relation between time which was performed MRI and enhancement was analyzed. The enhanced lesion in MRI was divided into five segments; Internal audiitory canal, Labyrinthine segment, Geniculate ganglion, Tympanic segment, Mastoid segment. In Bell's palsy, 20 of 25 patients(80%) had abnormal contrast enhancement of the facial nerve. The H-B grade and interval performed MRI from onset were directly proportionate to enhancement. That is to say, Severe facial palsy short interval show high possibility of enhancement. There was no relation between subjective causes and enhanced site of facial nerve in MRI. Also Clinical symptoms didn't coincide with MRI findings.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.393-396
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• 2011

In this paper, we propose a constrained alternating least squares nonnegative matrix factorization algorithm (cALSNMF) to detect active brain regions from single subject's task-related fMRI data. In cALSNMF, we define a new cost function which considers the uncorrelation and noisy problems of fMRI data by adding decorrelation and smoothing constraints in original Euclidean distance cost function. We also generate a novel training procedure by modifying the update rules and combining with optimal brain surgeon (OBS) algorithm. The experimental results on visuomotor task fMRI data show that our cALSNMF fits fMRI data better than original ALSNMF in detecting task-related brain activation from single subject's fMRI data.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1066-1082
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• 2021

Incidental adnexal masses considered indeterminate for malignancy are commonly observed on ultrasonography. Multiparametric MRI is the imaging modality of choice for the evaluation of sonographically indeterminate adnexal masses. Conventional MRI enables a confident pathologic diagnosis of various benign lesions due to accurate tissue characterization of fat, blood, fibrous tissue, and solid components. Additionally, functional imaging sequences, including perfusion- and diffusion-weighted imaging, improve the diagnostic efficacy of conventional MRI in differentiating benign from malignant adnexal masses. The ovarian-adnexal reporting and data system (O-RADS) MRI was recently designed to provide consistent interpretations in assigning risk of malignancy to ovarian and other adnexal masses, and to provide a management recommendation for each risk category. In this review, we describe the clinical application of multiparametric MRI for the evaluation of adnexal masses and introduce the O-RADS MRI risk stratification system.

• Journal of Korea Multimedia Society
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• v.22 no.10
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• pp.1168-1177
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• 2019

In order to diagnose and prevent Alzheimer's Disease (AD), it is becoming increasingly important to develop a CAD(Computer-aided Diagnosis) system for AD diagnosis, which provides effective treatment for patients by analyzing 3D MRI images. It is essential to apply powerful deep learning algorithms in order to automatically classify stages of Alzheimer's Disease and to develop a Alzheimer's Disease support diagnosis system that has the function of detecting hippocampus and CSF(Cerebrospinal fluid) which are important biomarkers in diagnosis of Alzheimer's Disease. In this paper, for AD diagnosis, we classify a given MRI data into three categories of AD, mild cognitive impairment, and normal control according by applying 3D brain MRI image to the Faster R-CNN model and detect hippocampus and CSF in MRI image. To do this, we use the 2D MRI slice images extracted from the 3D MRI data of the Faster R-CNN, and perform the widely used majority voting algorithm on the resulting bounding box labels for classification. To verify the proposed method, we used the public ADNI data set, which is the standard brain MRI database. Experimental results show that the proposed method achieves impressive classification performance compared with other state-of-the-art methods.

• Health Policy and Management
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• v.18 no.2
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• pp.1-18
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• 2008

As medical insurance had been implemented for Magnetic Resonance Imaging (MRI) from January 1, 2005, this study investigated whether there had been any change in the amount of the medical care utilization of patients who undertook MRI before and after the insurance coverage, and was to examine factors affecting the amount of medical care utilization of MRI. Data were collected from patients who undertook MRI before and after the insurance coverage for a year at a general hospital in Kyeanggi-do. $X^2$ and t-test were used for the analysis of their general characteristics, the number of MRI, and its medical costs before and after the insurance coverage, and hierarchical multiple regression analysis for the factors affecting the amount of the medical care utilization of MRI. The results of this study were as follows. First, the number of MRI after the insurance coverage was significantly decreased. Second, there was no significant difference in the total medical costs of MRI after the insurance coverage, but a significant difference was found in patient's share of medical costs. Third, six variables were found to be affecting the amount of the medical care utilization of MRI, and the variables showed to lead the number of MRI decrease after the insurance coverage. These six factors explained 21.4% of the total number of MRI. As MRI had been covered by insurance, the use of MRI and patient's share of the costs were deceased, but the total medical costs were not affected. Reasons for that could be found in that MRI insurance, different from the case of CT insurance coverage, was allowed not to cover some items and the kinds of diseases subjected to the insurance coverage were extremely limited, lowering insurance prescription rate. In addition to that, the average medical cost of MRI was not changed after the insurance coverage. Therefore, as future measures for the MRI insurance, coverage, it should be considered to allow insurance coverage to no coverage items and to expand the scope of benefit coverage, or to lower patient's share of the costs. Furthermore, researches should be done to explore how recipients will act and how suppliers will react if the coverage is expanded, including expanding the scope of coverage and reducing patient's share of the costs, as well as to conduct research on its economic analysis according to case mix.

• Smart Media Journal
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• v.13 no.6
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• pp.90-97
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• 2024

This paper focuses on detecting Alzheimer's Disease (AD). The most usual form of dementia is Alzheimer's disease, which causes permanent cause memory cell damage. Alzheimer's disease, a neurodegenerative disease, increases slowly over time. For this matter, early detection of Alzheimer's disease is important. The purpose of this work is using Magnetic Resonance Imaging (MRI) to diagnose AD. A Convolution Neural Network (CNN) model, Reset, and VGG the pre-trained learning models are used. Performing analysis and validation of layers affects the effectiveness of the model. T1-weighted MRI images are taken for preprocessing from ADNI. The Dataset images are taken from the Alzheimer's Disease Neuroimaging Initiative (ADNI). 3D MRI scans into 2D image slices shows the optimization method in the training process while achieving 96% and 94% accuracy in VGG 16 and ResNet 18 respectively. This study aims to classify AD from brain 3D MRI images and obtain better results.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.310-313
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• 1996

In this study, we developed three dimensional FDG brain PET and MRI coregistration technique. The boundaries of the head in PET and MRI were segmented using sinogram of emission PET scan and T1-weighted MRI. We registered both boundaries by minimizing the mean Euclidean distance of those. To display the registered PET and MRI simultaneously, we used weighted normalization method and interleaving method.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.1
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• pp.42-62
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• 2011

Objective: This study was performed to investigate the effect of acupuncture at HT8 on brain activity in perimenopausal women using fMRI. Methods: 15 healthy perimenopausal women volunteered in the study. No stimulation, sham stimulation, duration of acupuncture treatment on HT8, and rotation of acupuncture treatment on HT8 were randomly given for 6 minutes, with 20 seconds' intervals. Results: 1. In comparison with sham stimulation(Sham-B) and duration of acupucture (S1-B, S1-Sham, S2-S1), the areas of fMRI signal activation areas were just like cases including no stimulation. But the areas of vision were activated in S1-Sham. 2. In comparison with duration of acupuncture(S1-B, S1-Sham, S2-S1) and rotation of acupuncture(S2-B, S2-Sham, S2-S1), the areas of vision were activated in duration of acupuncture, and Supplementary motor area(SMA) were especially activated in rotation of acupuncture. Conclusions: After using fMRI and analysing effect of acupuncture treatment at HT8, we could confirm that fMRI signal activation areas by acupuncture treatment at HT8 were different from areas by sham stimulation. And according to acupuncture stimulation methods with duration and rotation, etc, we could confirm the specific reactions of series, and could get useful basic data for research of acupuncture from now on.