• Title/Summary/Keyword: functional Magnetic Resonance Imaging

Search Result 313, Processing Time 0.027 seconds

Advanced neuroimaging techniques for evaluating pediatric epilepsy

  • Lee, Yun Jeong
    • Clinical and Experimental Pediatrics
    • /
    • v.63 no.3
    • /
    • pp.88-95
    • /
    • 2020
  • Accurate localization of the seizure onset zone is important for better seizure outcomes and preventing deficits following epilepsy surgery. Recent advances in neuroimaging techniques have increased our understanding of the underlying etiology and improved our ability to noninvasively identify the seizure onset zone. Using epilepsy-specific magnetic resonance imaging (MRI) protocols, structural MRI allows better detection of the seizure onset zone, particularly when it is interpreted by experienced neuroradiologists. Ultra-high-field imaging and postprocessing analysis with automated machine learning algorithms can detect subtle structural abnormalities in MRI-negative patients. Tractography derived from diffusion tensor imaging can delineate white matter connections associated with epilepsy or eloquent function, thus, preventing deficits after epilepsy surgery. Arterial spin-labeling perfusion MRI, simultaneous electroencephalography (EEG)-functional MRI (fMRI), and magnetoencephalography (MEG) are noinvasive imaging modalities that can be used to localize the epileptogenic foci and assist in planning epilepsy surgery with positron emission tomography, ictal single-photon emission computed tomography, and intracranial EEG monitoring. MEG and fMRI can localize and lateralize the area of the cortex that is essential for language, motor, and memory function and identify its relationship with planned surgical resection sites to reduce the risk of neurological impairments. These advanced structural and functional imaging modalities can be combined with postprocessing methods to better understand the epileptic network and obtain valuable clinical information for predicting long-term outcomes in pediatric epilepsy.

MRI(Magnetic Resonance Imaging)의 원리와 응용

  • 오창현
    • Journal of the Korean Magnetics Society
    • /
    • v.6 no.4
    • /
    • pp.272-276
    • /
    • 1996
  • 1948년 Harvard 대학의 Purcell교수와 Stanford 대학의 Bloch교수가 핵자기 공명(Nuclear Magnetic Resonance : NMR) 현상을 발견한 이래로 NMR은 물질의 분자단위에서 화학적, 물리학적 성질을 밝혀내는 탁월한 방법으로 널리 이용되어 왔다. NMR 현상을 이용한 영상촬영법(Magnetic Resonance Imaging, MRI)은 1970년대초 Lauterber와 Damadian 교수가 처음 영상을 얻을 수 있다는 가능성을 제시한 이후 급속한 발전을 하여 1980년대 초에는 Moore와 Holland에 의해 의학분야에 응용 가능할 정도의 영상이 얻어졌다. 1980년대 중반부터 상용화 되었으며 최근 그 기법도 NMR현상과 연관된 파라미터인 $T_{1}$, $T_{2}$는 물론 혈류의 속도, 자화율, 확산(Diffusion), Perfusion의 영상기법을 비롯해 혈관조영술(MR Angiography), 뇌기능영상(Functional Imaging)등 과거에는 상상도 할 수 없었던 다양한 영상기법 개발되었다. 여기서는 먼저 MRI의 원리를 설명한 후 MRI의 여러 촬영기법들과 그 응용에 관해 설명하겠다.

  • PDF

Accelerated Resting-State Functional Magnetic Resonance Imaging Using Multiband Echo-Planar Imaging with Controlled Aliasing

  • Seo, Hyung Suk;Jang, Kyung Eun;Wang, Dingxin;Kim, In Seong;Chang, Yongmin
    • Investigative Magnetic Resonance Imaging
    • /
    • v.21 no.4
    • /
    • pp.223-232
    • /
    • 2017
  • Purpose: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. Materials and Methods: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. Results: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. Conclusion: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.

Analysis of the Degenerative Disc Change and Its Relationship to Living Function (추간판의 퇴행성 변화와 생활기능의 관련성 분석)

  • Sin, Jung-Sub;Yoon, Se-Won
    • The Journal of Korean Physical Therapy
    • /
    • v.18 no.6
    • /
    • pp.43-49
    • /
    • 2006
  • Purpose: Changes of degenerative disc have been analyzed or with the Magnetic Resonance Imaging (MRI) to assign appropriate meaning, and the relationship between the degenerative changes of the discs and its living function has been evaluated through the living function evaluation scores collected by functional rating index. Methods: in April, 2006, a physical examination was conducted for physical laborers to be employed as on-site laborer in a steel industrial complex located at a region. A month later, these 20 laborers who participated in lumbar vertebra MRI tests have been investigated for one-to-one mobile phone functional rating index test. Excluding 3 of 14 respondents whom scored 0 in functional rating index, the rest of respondents' degenerative disc grade changes shown in MRI and its relationship to living functional rating index have been performed. Results: The Dabbs method of measuring disc height resulted to show significant increase as the disc height changes from L1-2 level to L5-S1 level (p<0.01). However, there was no statistical significance with a relationship between disc height and functional rating index, and disc height average. The Magnetic Resonance Imaging analysis regard on the degree of disc degeneration and its relationship to living functional rating proved to have significant relationship (p<0.05). Conclusion: The degenerative changes monitored by Magnetic Resonance Imaging show significant relationship (p<0.05) to living function. However, this relationship could vary depend upon the characteristics of study population. So, it suggested that the future studies should be performed by considering population's age and job career.

  • PDF

Brain Areas Subserving Torrance Tests of Creative Thinking: An Functional Magnetic Resonance Imaging Study

  • Hahm, Jarang;Kim, Kwang Ki;Park, Sun-Hyung;Lee, Hyo-Mi
    • Dementia and Neurocognitive Disorders
    • /
    • v.16 no.2
    • /
    • pp.48-53
    • /
    • 2017
  • Background and Purpose Torrance Tests of Creative Thinking (TTCT) is a well-known and commonly used measure of creativity. However, the TTCT-induced creative hemodynamic brain activity is rarely revealed. The purpose of this study is to elucidate the neural correlates of creative thinking in the setting of a modified version of the figural TTCT adapted for an functional magnetic resonance imaging (fMRI) experiment. Methods We designed a blocked fMRI experiment. Twenty-five participants (11 males, 14 females, mean age $19.9{\pm}1.8$) were asked to complete the partially presented line drawing of the figural TTCT (creative drawing imagery; creative). As a control condition, subjects were asked to keep tracking the line on the screen (line tracking; control). Results Compared to the control condition, creative condition revealed greater activation in the distributed and bilateral brain regions including the left anterior cingulate, bilateral frontal, parietal, temporal and occipital regions as shown in the previous creativity studies. Conclusions The present revealed the neural basis underlying the figural TTCT using fMRI, providing an evidence of brain areas encompassing the figural TTCT. Considering the significance of a creativity test for dementia patients, the neural correlates of TTCT elucidated by this study may be valuable to evaluate the brain function of patients in the clinical field.

Effects of Therapeutic Exercise on Pain, Physical Function, and Magnetic Resonance Imaging Findings in a Patient with Multilevel Lumbar Disc Herniation: A Case Report

  • Kim, Ahram;Lee, Hoseong
    • Journal of International Academy of Physical Therapy Research
    • /
    • v.10 no.1
    • /
    • pp.1725-1733
    • /
    • 2019
  • Background: In some clinical guidelines followed in clinical practice, nonsurgical treatments are recommended as the primary intervention for patients with lumbar disc herniation (LDH). However, the effect of a therapeutic exercise program based on stabilization of the lumbar spine for treatment of multilevel LDH has not been evaluated thoroughly. Objective: To investigate the effects of therapeutic exercise on pain, physical function, and magnetic resonance imaging (MRI) findings in a patient with multilevel LDH. Design: Case Report Methods: A 43-year-old female presented with low back pain, radicular pain and multilevel LDH (L3-L4, L4-L5, L5-S1). The therapeutic exercise program was conducted. in 40-min sessions, three times a week, for 12 weeks. Low back and radicular pain, lumbar disability, and physical function were measured before and after 6 and 12 weeks of the exercise program. MRI was performed before and after 12 weeks of the program. Results: After 6 and 12 weeks of the therapeutic exercise, low back and radicular pain and lumbar disability had decreased, and lumbar range of motion (ROM) was improved bilaterally, compared with the initial values. Also improved at 6 and 12 weeks were isometric lumbar strength and endurance, and the functional movement screen score. The size of disc herniations was decreased on MRI obtained after 12 weeks of therapeutic exercise than on the pre-exercise images. Conclusions: We observed that therapeutic exercise program improved spinal ROM, muscle strength, functional capacity, and size of disc herniation in LDH patient.

Robust group independent component analysis (로버스트 그룹 독립성분분석)

  • Kim, Hyunsung;Li, XiongZhu;Lim, Yaeji
    • The Korean Journal of Applied Statistics
    • /
    • v.34 no.2
    • /
    • pp.127-139
    • /
    • 2021
  • Independent Component Analysis is a popular statistical method to separate independent signals from the mixed data, and Group Independent Component Analysis is an its multi-subject extension of Independent Component Analysis. It has been applied Functional Magnetic Resonance Imaging data and provides promising results. However, classical Group Independent Component Analysis works poorly when outliers exist on data which is frequently occurred in Magnetic Resonance Imaging scanning. In this study, we propose a robust version of the Group Independent Component Analysis based on ROBPCA. Through the numerical studies, we compare proposed method to the conventional method, and verify the robustness of the proposed method.

Acupuncture stimulation for motor cortex activities: Evidence from 3T functional MRI study

  • 최보영;전신수;유승식;최기순;박상동;임은철;정성택;이형구;서태석
    • Proceedings of the KSMRM Conference
    • /
    • 2003.10a
    • /
    • pp.85-85
    • /
    • 2003
  • Purpose: To investigate whether or not acupuncture of GB34 produces a significant response of the modulation of somatomotor areas by functional magnetic resonance imaging (fMRI) study. Materials and methods: The acupoint, GB34, located in the back of the knee, is known to be effective in recovering motor function after stroke. Using 3T MRI scanner, functional MR imaging of the whole brain was peformed in 12 normal healthy subjects during two stimulation paradigms; acupuncture manipulation on GB34 and sham points. This study investigates the activation of the motor cortex elicited by a soft and an intensified stimulation of GB 34.Three different paradigms were carried out to detect any possible modulation of the Blood Oxygenation Level Dependent (BOLD) response in the somatomortor area to motor stimulation through acupuncture.

  • PDF