• Title/Summary/Keyword: Functional MRI

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Disturbed Functional Asymmetry of Sensorimotor Cortex in Schizophrenia: A Study with Functional Magnetic Resonance Imaging (정신분열증에서 감각운동피질의 기능적 비대칭성의 장애: 기능적 자기공명영상을 이용한 연구)

  • Ahn, Kook-Jin;Chae, Jeong-Ho;Kim, Tae;Kim, Euy-Neyng;Lee, Jee-Mun;Choi, Kyu-Ho;Hahn, Seong-Tai
    • Investigative Magnetic Resonance Imaging
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    • v.4 no.1
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    • pp.52-57
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    • 2000
  • Purpose : The purpose of this study was to investigate the pattern of cerebral response to motor tasks in patients with schizophrenia compared with normal subjects using functional MRI. Materials and methods ; Nine right handed-schizophrenic patients and six right-handed normal subjects were included. We used right hand movement as task. Series of 120 consecutive echo-planar images per section were acquired during three cycles of task and rest activations. Lateralization index of cortical response was measured and compared between patients and normal subjects. Results ; Right hand motor task was associated with greater activation in left sensorimotor cortex than the right in normal subjects. Schizophrenia patients showed relatively decreased activation in left cortex and increased activation in right cortex compared with normal subjects. In one patient, reversed lateralization was noted. Conclusion : Normal hemispheric asymmetry of cortical response to motor task was found in different pattern in schizophrenia. Our result is consistent with functional disturbance of motor circuitry in this disorder. Functional MRI will play an important role in diagnosis and research of this disorder.

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Comparative Study of Functional Magnetic Resonance Imaging by Global Scaling Analysis (Global Scaling 분석방법에 따른 기능적 자기공명영상의 비교 연구)

  • Yoo, Dong-Soo
    • Investigative Magnetic Resonance Imaging
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    • v.10 no.1
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    • pp.26-31
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    • 2006
  • Purpose : To evaluate the effect of global scaling analysis on brain activation for sensory and motor functional MR imaging study. Materials and methods : Four normal subjects without abnormal neurological history were included. Arm extension-flexion movement was used for motor function and 1KHz pure tone stimulation was used for auditory function. Functional magnetic resonance imaging was performed at 3T MRI (GE, Milwaukee, USA) using BOLD-EPI technique and SPM2 was employed for data analysis. On data analysis, the brain activation images were obtained with and without global scaling by fixing other parameters such as motion correction and realignment. Results : The difference in brain activation between no scaling and global scaling was not large in case of right upper extremity movement (p<0.000001). For auditory test, brain activation with global scaling showed larger activation than that of without global scaling (p<0.05). Conclusion : A caution must be taken into account when analyzing functional imaging data with global scaling especially for functional study of small local BOLD signal change.

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Cortical Activation by Transcranial Direct Current Stimulation and Functional Electrical Stimulation in Normal Subjects: 2 Case Studies (정상 성인에서 경두개 직류 전류자극과 기능적 전기자극에 의한 대뇌피질의 활성화: 사례연구)

  • Kwon, Yong-Hyun;Kwon, Jung-Won;Park, Sang-Young;Jang, Sung-Ho
    • The Journal of Korean Physical Therapy
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    • v.23 no.1
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    • pp.77-82
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    • 2011
  • Purpose: Recently, many studies have demonstrated that application of external stimulation can modulate cortical excitability of the human brain. We attempted to observe cortical excitability using functional magnetic resonance imaging (fMRI) during the application of transcranial direct current stimulation (tDCS) or functional electrical stimulation (FES). Methods: We recruited two healthy subjects without a history of neurological or psychiatric problems. fMRI scanning was done during? each constant anodal tDCS and FES session, and each session was repeated three times. The tDCS session consisted of three successive phases (resting phase: 60sec dummy cycle: 10sec tDCS phase: 60sec). The FES session involved stimulation of wrist extensor muscles over two successive phase (resting phase: 15sec FES phase: 15sec). Results: The average map of the tDCS and FES analyses showed that the primary sensory-motor cortex area was activated in all subjects. Conclusion: Our findings show that cortical activation can be induced by constant anodal tDCS and FES. They suggest that the above stimuli have the potential for facilitating brain plasticity and modulating neural excitability if applied as specific therapeutic interventions for brain injured patients.

Recent Advances on Resting State Functional Abnormalities of the Default Mode Network in Social Anxiety Disorder (사회불안장애에서 내정상태회로의 휴지기 기능 이상에 관한 최신 지견)

  • Yoon, Hyung-Jun;Seo, Eun Hyun;Kim, Seung-Gon
    • Anxiety and mood
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    • v.14 no.2
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    • pp.63-70
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    • 2018
  • It has been suggested that aberrant self-referential processing (SRP) is one of the important components of the explanatory models of social anxiety disorder (SAD). The default mode network (DMN), which reflects intrinsic brain functions, is known to play a critical role in SRP. Recently, resting state functional magnetic resonance imaging (fMRI) research on the functional connectivity in the brain network has gained greater attention as a tool to elucidate the neurobiological basis of various psychiatric disorders. We reviewed resting state fMRI studies that investigated the resting state functional connectivity (RSFC) of the DMN in SAD. Despite of the heterogeneity of the analytic methods and occasional negative findings, most studies consistently reported abnormalities of RSFC within the DMN, suggesting that the DMN may be significant neural correlates of aberrant SRP in SAD. Also, changes in RSFC of the DMN are associated with clinical improvements of therapeutic interventions. Moreover, emerging findings provide the basis for potential use of RSFC as a complementary method in diagnosis of SAD. Ongoing and future research to investigate RSFC of the DMN could broaden our understanding regarding the neurobiological basis of SAD, and contribute to the development of novel treatments for SAD.

The Latest Trend of Dynamic MR Defecography for the Chronic Constipation Patient (만성 기능성 변비 환자에서 동적 MR Defecography의 최신동향)

  • Yoon, Seok-Hwan
    • Journal of radiological science and technology
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    • v.27 no.4
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    • pp.17-21
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    • 2004
  • With advancement of the medical imaging technology, the dynamic pelvic MRI (magnetic resonance imaging) has been introduced and used for dynamic MR defecography to improved diagnosis of the patients. At the early stage of its use, it was mostly used to diagnose enterocele or cystocele, then its use was extended to diagnose the organ prolapse and other dysfunctional pelvis organs. There now have been many reports of other diseases such as the functional constipation and others. This paper introduces the pelvis MRI and the dynamic MR defecography and reports the future trend in their clinical applications. Until recently, the studies with pelvic MRI were mostly focused on observing the movement of the pelvis in the supine position. Yang and 26 others reported good result in observing the patients with the pelvic organ prolapse by using the pubococcygeal line as the anatomical index. Using the fast gradient recalled acquisition (fast GRASS), they compared cystocoele, genitourinary prolapse, enterocoele and rectocoele with the control group. Kruyt et al. observed the posterior compartment and reported that MRI was more helpful than the fluoroscopy. Healy et al. applied the dynamic MRI test on the patients with constipation or incontinence as well as the control group without those symptoms. Since then, MRI technology has further advance by Lienemann, who was able to attain the more detailed images using the fast T2 weighted turbo spin echo technology, and others. If its limitation in diagnosing intussusception and the like, since the observation can be made only from the supine position, can be overcome with open MR or others, it is envisages that the method can eventually replace the radiological defecography.

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Activations of Cerebral and Cerebellar Cortex Induced by Repetitive Bilateral Motor Excercise (반복적 양측 운동학습에 따른 대뇌 및 소뇌 피질 활성화)

  • Tae, Ki-Sik;Song, Sung-Jae;Kim, Young-Ho
    • Journal of Biomedical Engineering Research
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    • v.28 no.1
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    • pp.139-147
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    • 2007
  • The aim of this study was to evaluate effects of short-tenn repetitive-bilateral excercise on the activation of motor network using functional magnetic resonance imaging (fMRI). The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer Assessments (FMA) were performed every two weeks during the training. We compared cerebral and cerebellar cortical activations in two different tasks before and after the training program: (1) the only unaffected hand movement (Task 1); and (2) passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI was performed at 3T with wrist flexion-extension movement at 1 Hz during the motor tasks. All patients showed significant improvements of FMA scores in their paretic limbs after training. fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral sensorimotor cortex but increased in contralateral sensorimotor cortex and ipsilateral cerebellum. Task 2 showed cortical reorganizations in bilateral sensorimotor cortex, premotor area, supplemetary motor area and cerebellum. Therefore, this study demonstrated that plastic changes of motor network occurred as a neural basis of the improvement subsequent to repetitive-bilateral excercise using the symmetrical upper-limb ann motion trainer.

Neural Switching Mechanism in the late Korean-English bilinguals by Event-Related fMRI

  • Kim, Jeong-Seok
    • Journal of Biomedical Engineering Research
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    • v.29 no.4
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    • pp.272-277
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    • 2008
  • Functional MRI technique was used in this study for examining the language switching mechanisms between the first language (L1) and the second language (L2). Language switching mechanism is regarded as a complex task that involves an interaction between L1 and L2. The aim of study is to find out the brain activation patterns during the phonological process of reading real English words and English words written in Korean characters in a bilingual person. Korean-English bilingual subjects were examined while they covertly read four types of words native Korean words, Korean words of a foreign origin, English words written in Korean characters, and English words. The fMRI results reveal that the left hemispheric language-related regions at the brain, such as the left inferior frontal, superior temporal, and parietal cortices, have a greater response to the presentation of English words written in Korean characters than for the other types of words, in addition, a slight difference was observed in the occipital-temporal lobe. These results suggest that a change in the brain circuitry underlying the relational processes of language switching is mainly associated with general executive processing system in the left prefrontal cortex rather than with a similarity-based processing system in the occipital-temporal lobes.

Case study on the couple therapy for family violence : Focusing on the wife residing in a shelter (가정폭력에 대한 부부치료 사례 분석 : 가정폭력 쉼터에 거주하는 부인을 대상으로)

  • Park, Tai-Young;Park, So-Young
    • Journal of Families and Better Life
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    • v.28 no.5
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    • pp.75-88
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    • 2010
  • This study analyzed a family therapy case which dealt with family violence and was consisted of 14 sessions. The therapeutic perspective for this case was MRI model, a strategic family therapy model which emphasizes attempted solutions and interactions. The results of this study were as follows. This study found the interaction process of occurring family violence. When the husband attempted conversations with his wife after drinking, the wife who was anxious and dreadful avoided conversation. This avoidance made the husband felt rejected feeling, and he battered his wife. The avoidance of conversation, an attempted solution of wife, was made from her frame of reference which was affected from her original family context and the couple's communication style in ordinary times. The therapist made the couple recognize their attempted solutions were not effective, and he helped them begin new solutions or coping behaviors. This intervention process was long and hard, but the couple changed their attempted solutions to new solutions which were clear communication styles and functional interaction process. This study results showed the effectiveness of couple therapy on family violence. The effectiveness of MRI model was also proved from the study. The results of study will be helpful to the family therapists and counsellors in the field of family violence.

The Ongoing Effect of Transcranial Direct Current Stimulation on both the Hemispheres: Single Case fMRI Study

  • Kwon, Jung-Won;Son, Sung-Min;Kim, Chung-Sun;Cho, In-Sul
    • The Journal of Korean Physical Therapy
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    • v.23 no.6
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    • pp.49-53
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    • 2011
  • Purpose: The purpose of this study is to investigate whether dual-hemisphere transcranial direct current stimulation (tDCS) could induce more cortical activity, compared to single-hemisphere, using functional MRI (fMRI). Methods: One right-handed healthy subject was recruited. Three phases of dual-hemisphere tDCS (i.e. anodal tDCS over the left-dominant primary sensoriomotor cortex (SM1) and cathodal tDCS over the right-non dominant SM(1) were consecutively delivered on to a subject, during fMRI scanning. The voxel count and the intensity index in the averaged cortical map were analyzed among the three tDCS phases. Results: Our result showed that cortical activation was observed on all the three phases of the dual-hemisphere tDCS. Voxel count and intensity index were as following; 912 and 4.07 in the first phase, 1102 and 3.90 in the second phase, 1031 and 3.80 in the third phase. Conclusion: This study demonstrated that application of the dual-hemisphere tDCS could induce cortical activity and maintain to recruit cortical neurons. Our findings suggested that application of dual-hemisphere tDCS could produce efficiency of the ongoing tDCS effect to facilitate cortical excitability.

Difference of fMRI between the Tickling and Sensory Stimulation Using 3.0 Tesla MRI (3.0T 자기공명영상장치를 이용한 사람의 간지럼자극과 감각중추 자극의 활성화 차이)

  • Khang, Hyun-Soo;Lim, Ki-Seon;Han, Dong-Kyoon
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.286-294
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    • 2010
  • This study was performed to identify the cerebral network associated with sensation through the tickling stimulation, which is distinctive from the rest of other networks processing normal stimulation and to investigate the difference of laughing mechanism which is closely related to tickling using functional MRI(fMRI). A 16 healthy volunteers (mean age: 28.9) on a 3.0T MR scanner during two sensation conditions. Counterbalanced stimulus were presented across the participants, and the stimulation was used block design. Acquired data was analyzed by the statistical parametric mapping (SPM 99). Subject and group analysis was performed. Individual analysis showed the activation of somatic sensation area in both tasks and the tickling sensation test showed more activated area in the Wernicke's area(BA40) compared to the normal sensation. The group analysis result shows that under normal stimulations, both sides of somatosensory cortices(BA 1,2 and 3) were activated and under tickling stimulation, not only the cortices but also those huge activation on thalamus, cingulate gyrus and insular lobe were detected. When the tickling was stopped, significant activations were shown in right cingulate gyrus, left MFG area and left insular lobe. A cerebral area responsible for recognizing tickling sensation was examined and the primitive stimulation such as tickling is much closely related to laugh, which is an important factor for various social activities.