• 한국의학물리학회지:의학물리
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• 제24권4호
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• pp.237-242
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• 2013

뇌병변 등의 방사선 치료에 있어 CT (Computed Tomography) 영상만을 이용한 종양 체적(Tumor volume) 윤곽의 정확한 설정은 CT 영상의 부족한 연부조직 대조도 특성에 의하여 한계를 가진다. 따라서 자기공명영상(Magnetic Resonance Images, MRI)이 보다 정확한 목표 체적의 윤곽을 그려내기 위해 광범위 하게 사용되고 있다. 치료계획을 위해 획득한 자기공명영상에 진단단계에서 얻어진 CT영상의 전자밀도를 융합하는 방법과 자기공명 영상으로부터 만들어진 가상의 CT를 이용하는 방법 등이 자기공명 영상장치를 기반으로 한 방사선 치료 계획의 선량계산을 위하여 소개되어 왔다. 본 연구는 MRI기반의 선량계산의 가능성을 확인 해보기 위해 15명 환자의 진단 MR 영상을 통하여 Look Up Table (LUT)을 만들어 MRI 기반 선량계산과 기존의 CT 기반 선량계산을 비교 검증 하였다. 여기서 lMRI는 획득한 MR 영상에 LUT를 이용한 전자밀도 보정을 한 것이며 wMRI는 획득한 MR영상을 물 밀도로 동일화 시킨 것이다. 6 MV anterial 방향의 조사가 CT, lMRI, wMRI에 적용되어 치료계획으로 비교되었으며 또한 환자의 병변위치에 따라 2문 조사에서 5문 조사의 치료계획이 비교되었다. CT기반 치료계획을 기준으로 하여 등선량 분포와 DVH의 차이는 wMRI 보다 lMRI에서 더 적었으며 최대선량 차이가 91 cGy vs. 57 cGy, 평균선량이 74 cGy vs. 42 cGy, 최소선량 차이가 94 cGy vs. 53 cGy로 측정되어 각각의 선량 평가 면에서 그 차이가 wMRI보다 lMRI에서 더 적었다. 이러한 결과는 wMRI의 경우 공동내 선량계산에서 CT기반 선량계산과 차이가 나기 때문이다. 따라서 본 연구의 결과는 lMRI 기반 선량계산의 가능성이 있음을 보여준다.

• Korean Journal of Radiology
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• 제20권1호
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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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• 제17권3호
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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.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(C)
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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.

• 대한영상의학회지
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• 제82권5호
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• pp.1066-1082
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• 2021

초음파에서 우연히 접하는 자궁부속기 병변은 양성 병변이 더 흔하지만, 일부는 악성도가 애매한 병변으로 간주되어 추가적인 평가를 위해 다중매개변수 MRI가 필요하다. 고식적 MRI를 통해 해부학적 모양을 살피고, 지방, 출혈, 섬유성 조직, 고형성 조직 등 병변의 구성성분을 파악하여 많은 양성 종괴들을 정확하게 진단할 수 있다. 또한 추가적인 확산강조영상과 역동적 조영증강 기법의 관류영상으로 양성과 악성의 감별 진단 정확도를 높일 수 있다. 최근 자궁부속기 종괴의 악성 위험도를 평가하고, 각 위험도 군에 대한 적절한 조치를 권고하는데 있어 표준화된 의사소통이 가능하도록 하기 위해 난소-자궁부속기 MRI 보고 및 자료시스템(ovarian-adnexal reporting and data system MRI; 이하 O-RADS MRI)이 발표되었다. 본 종설에서는 자궁부속기 종괴의 악성도 예측 및 감별 진단을 위한 다중매개변수 MRI의 임상 적용과 O-RADS MRI에 대하여 기술하고자 한다.

• 한국멀티미디어학회논문지
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• 제22권10호
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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.

• 보건행정학회지
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• 제18권2호
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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.

• 스마트미디어저널
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• 제13권6호
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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.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.310-313
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• 1996

PET 방출스캔 영상과 MRI에서 추출한 머리 표피의 경계점들의 거리를 최소화하는 방법을 사용하여 두 영상의 위치정합을 시도하였다. 위치 정합된 두영상의 동시표현을 위하여 가중정규화 방법과 interleaving 방법을 시도하였다.

• 대한한방부인과학회지
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• 제24권1호
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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.