Segmentation of Scalp and Skull in brain MR Images Using Canny- Edge Level Set Method

( Ruoyu Du ),( Hyo Jong Lee ) 한국정보처리학회 2010 한국정보처리학회 학술대회논문집 Vol.17 No.2

In this paper, we present a novel automatic algorithm for scalp and skull segmentation in T1-weighted head MR images. First, the scalp and skull part are constructed by using intensity threshold. Second, the scalp outer surface is extracted based on an active level set method. Third, the skull inner surface is extracted using a canny edge detection algorithm. Finally, the fast sweeping, tagging and level set methods are applied to reconstruct surfaces from the detected points in three-dimensional space. The results of the new segmentation algorithm on MRI data acquired from eight persons were compared with manual segmented data. The average similarity indices for the scalp and skull segmented regions were equal to 84.42% for the test data.

Frontal Asymmetry Analysis of Theta Wave in the Audio Emotional Experiment Revealed by Event-related Spectral Perturbation

( Ruoyu Du ),( Hyo Jong Lee ) 한국정보처리학회 2014 한국정보처리학회 학술대회논문집 Vol.21 No.1

Hemispheric asymmetry in prefrontal activation have been proposed in two decades ago, as measured by electroencephalographic (EEG) power in the theta band (4-8Hz), is related to reactivity to affectively pleasure audio stimuli. In this study, we designed an emotional audio stimulus experiment in order to verify frontal EEG asymmetry by analyzing ERSP results. Thirty healthy college students volunteered the stimulus experiment with the standard IADS affective sounds. These affective sound clips are classified in three emotion states, happy, neutral and fear. ERSP image results revealed that there are the stronger responses of high arousal (fear and happy) in the left pre-frontal lobe, while the stronger responses of low arousal (neutral) in the right pre-frontal lobe. However, the high pleasure emotions (happy) can elicit greater relative right EEG activity, while the low and middle pleasure emotions (fear and neutral) can elicit the greater relative left EEG activity. Additionally, the most response differences of theta band have been found out in the medial frontal lobe, which is proved as the frontal midline theta.

Brain Extraction of MR Images

( Ruoyu Du ),( Hyo Jong Lee ) 한국정보처리학회 2010 한국정보처리학회 학술대회논문집 Vol.17 No.1

Extracting the brain from magnetic resonance imaging head scans is an essential preprocessing step of which the accuracy greatly affects subsequent image analysis. The currently popular Brain Extraction Tool produces a brain mask which may be too smooth for practical use to reduce the accuracy. This paper presents a novel and indirect brain extraction method based on non-brain tissue segmentation. Based on ITK, the proposed method allows a non-brain contour by using region growing to match with the original image naturally and extract the brain tissue. Experiments on two set of MRI data and 2D brain image in horizontal plane and 3D brain model indicate successful extraction of brain tissue from a head.

Constructing De-identified Brain Model using Deformable Registration

Ruoyu Du(두약유),Hyo Jong Lee(이효종) 한국정보과학회 2013 정보과학회 컴퓨팅의 실제 논문지 Vol.19 No.4

자기공명영상(Magnetic Resonance Image)의 3차원 구성은 두뇌 연구에 관한 임상 진단과 적용 연구분야 모두에서 필수적인 과정이다. 그러나, 이와 같은 3차원 영상의 구성에 따른 문제로는 환자의 신원이 노출될 수 있다는 것이다. 미국의 경우 1996년에 제정된 건강보험의 이동과 회계에 관한 법(HIPAA)의 개인정보 보호법에 의하여 환자들의 신원이 밝혀질 수 있는 개인정보는 연구목적으로 사용될 수 없으며, 이러한 정보가 제거된(de-identification)후에만 가능하도록 하였다. 이와 같은 환자의 신원 노출문제를 해결하기 위하여 기존 연구에서 활용된 자기공명영상 저장소의 데이터에 변형 정합기법을 적용하였다. 얼굴정보가 노출되는 MR 영상의 특징점들을 익명의 얼굴로 대체하여 신원을 은닉시키는 두뇌 형성 모델 알고리즘을 제안하였다. Three-dimensional (3-D) reconstruction of magnetic resonance (MR) brain imaging study is a routine component of both clinical practice and translational research. A problem of such reconstructions is the creation of a potentially recognizable face. The Health Insurance Portability and Accountability Act of 1996 (HIPAA) Privacy Rule requires that individually identifiable health information may not be used for research unless identifiers that may be associated with the health information are removed (de-identification). In this paper, to address this problem, MR images were selected from existing research repositories and a deformable registration has been applied to those MR images. The algorithm of de-identified brain construction model is proposed to substitute the facial features of identifiable MR images with an anonymous face.

Segmentation of Scalp in Brain MR Images Based on Region Growing

( Ruoyu Du ),( Hyo Jong Lee ) 한국정보처리학회 2009 한국정보처리학회 학술대회논문집 Vol.16 No.2

The aim in this paper is to show how to extract scalp of a series of brain MR images by using region growing segmentation algorithm. Most researches are all forces on the segmentation of skull, gray matter, white matter and CSF. Prior to the segmentation of these inner objects in brain, we segmented the scalp and the brain from the MR images. The scalp mask makes us to quickly exclude background pixels with intensities similar those of the skull, while the brain mask obtained from our brain surface. We make use of connected threshold method (CTM) and confidence connected method (CCM). Both of them are two implementations of region growing in Insight Toolkit (ITK). By using these two methods, the results are displayed contrast in the form of 2D and 3D scalp images.

A Visualization System of Brain MR image based on VTK

( Ruoyu Du ),( Hyo Jong Lee ) 한국정보처리학회 2012 한국정보처리학회 학술대회논문집 Vol.19 No.1

VTK is a free but professional development platform for images three-dimensional (3D) reconstruction and processing. It is powerful, open-source, and users can customize their own needs by self-development of great flexibility. To give the doctors more and detailed information by simulate dissection to the 3-D brain MRI image after reconstruction. A Visualization System (VS) is proposed to achieve 3D brain reconstruction and virtual dissection functions. Based on the free VTK visualization development platform and Visual Studio 2010 IDE development tools, through C++ language, using real people’s MRI brain dataset, we realized the images 3D reconstruction and also its applications and extensions correspondingly. The display effect of the reconstructed 3D image is well and intuitive. With the related operations such as measurement, virtual dissection and so on, the good results we desired could be achieved.

Simplification of LIDAR Data for Building Extraction Based on Quad-tree Structure

( Ruoyu Du ),( Hyo Jong Lee ) 한국정보처리학회 2011 한국정보처리학회 학술대회논문집 Vol.18 No.2

LiDAR data is very large, which contains an amount of redundant information. The information not only takes up a lot of storage space but also brings much inconvenience to the LIDAR data transmission and application. Therefore, a simplified method was proposed for LiDAR data based on quad-tree structure in this paper. The boundary contour lines of the buildings are displayed as building extraction. Experimental results show that the method is efficient for point’s simplification according to the rule of mapping.

인간 컴퓨터 상호작용 : 청각자극에 따른 세타파와 알파파의 스펙트럼적 반응

( Ruoyu Du ),이효종 ( Hyo Jong Lee ) 한국정보처리학회 2014 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.3 No.10

감정을 유발하는 청각자극에 따라 발생되는 EEG(Electroencephalographic) 스펙트럼 강도와 감정 반응 간의 상관관계는 중요한 변수이다. 약 20여 년 전 쾌감을 주는 청각자극에 대하여 측정된 신호의 강도가 전전두엽에서 비대칭적으로 반응을 보였다는 연구 결과가 발표되었다. 본 연구에서는 자극관련 스펙트럼적 반응(Event-related Spectral Perturbation: ERSP)이 전두엽에서 비대칭적으로 발생되는지 고찰하기 위하여 청각자극 실험을 수행하였다. 30명의 건강한 대학생 지원자들이 IADS(International Affective Digital Sounds) 실험에 참여하였다. 이 청각자극은 행복, 공포, 그리고 중립의 3단계로 분류되었으며, 데이터의 분석은 세타파(4-8Hz)와 알파파(8-13Hz)에서 이루어졌다. 알파대역의 ERSP 지도는 오른쪽 전두엽에서 행복감과 공포감의 자극에서 높은 신호의 강도를 보여주는 반면 중립성 자극에서는 왼쪽 전두엽에서 높은 신호가 발생되었다. 그러나 세타파는 행복감과 공포감의 자극에 따라 좌측 전두엽에서 높은 신호가 나타나는 반면, 중립적 자극에 따라 우측 전두엽에서 높은 신호를 보여주었다. 높은 쾌감성 자극(행복)은 상대적으로 우측 전두엽에서 높은 EEG 신호가 측정되었으며, 낮은 쾌감성 자극(중립과 공포)은 왼쪽 전두엽에서 측정되었다. 또한 가장 큰 세타파의 변화가 전두엽의 중앙에서 발생되었다. 알파파에서 행복한 청각자극에 가장 강한 신호가 전두엽 전체에서 관찰되었다. 이 결과들은 기존의 감정들과 일치되며, 세타파와 알파파가 감정처리에서 중요한 역할을 하고 있음을 시사한다. The correlations between electroencephalographic (EEG) spectral power and emotional responses during affective sound clip listening are important parameters. Hemispheric asymmetry in prefrontal activation have been proposed in two decades ago, as measured by power value, is related to reactivity to affectively pleasure audio stimuli. In this study, we designed an emotional audio stimulus experiment in order to verify frontal EEG asymmetry by analyzing Event-related Spectral Perturbation (ERSP) results. Thirty healthy college male students volunteered the stimulus experiment with the standard IADS(International Affective Digital Sounds) clips. These affective sound clips are classified in three emotion states, high pleasure-high arousal (happy), middle pleasure-low arousal (neutral) and low pleasure-high arousal (fear). The analysis of the data was performed in both theta (4-8Hz) and alpha (8-13Hz) bands. ERSP maps in the alpha band revealed that there are the stronger power responses of high pleasure (happy) in the right frontal lobe, while the stronger power responses of middle-low pleasure (neutral and fear) in the left frontal lobe. Moreover, ERSP maps in the theta band revealed that there are the stronger power responses of high arousal (fear and happy) in the left pre-frontal lobe, while the stronger responses of low arousal (neutral) in the right pre-frontal lobe. However, the high pleasure emotions (happy) can elicit greater relative right EEG activity, while the low and middle pleasure emotions (fear and neutral) can elicit the greater relative left EEG activity. Additionally, the most differences of theta band have been found out in the medial frontal lobe, which is proved as the frontal midline theta. And there are the strongest responses of happy sounds in the alpha band around the whole frontal regions. These results are well suited for emotion recognition, and provide the evidences that theta and alpha powers may have the more important role in the emotion processing than previously believed.

Building De-identified Brain Model using Deformable Registration

Ruoyu Du,Hyo Jong Lee 한국정보과학회 2012 한국정보과학회 학술발표논문집 Vol.39 No.2C

Consistency of Optimized Facial Features through the Ages

Ruoyu Du,Hyo Jong Lee 보안공학연구지원센터 2013 International Journal of Multimedia and Ubiquitous Vol.8 No.5