• 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.

• 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.

• 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 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.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.676-687
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• 2020

Purpose To analyze the altered brain regions and intrinsic brain activity patterns in trauma-exposed firefighters without posttraumatic stress disorder (PTSD). Materials and Methods Resting-state functional MRI (rsfMRI) was performed for all subjects. Thirty-one firefighters over 40 years of age without PTSD (31 men; mean age, 49.8 ± 4.7 years) were included. Twenty-six non-traumatized healthy controls (HCs) (26 men; mean age, 65.3 ± 7.84 years) were also included. Voxel-based morphometry was performed to investigate focal differences in the brain anatomy. Seed-based functional connectivity analysis was performed to investigate differences in spontaneous brain characteristics. Results The mean z-scores of the Seoul Verbal Learning Test for immediate and delayed recall, Controlled Oral Word Association Test (COWAT) score for animals, and COWAT phonemic fluency were significantly lower in the firefighter group than in the HCs, indicating decreased neurocognitive function. Compared to HCs, firefighters showed reduced gray matter volume in the left superior parietal gyrus and left inferior temporal gyrus. Further, in contrast to HCs, firefighters showed alterations in rsfMRI values in multiple regions, including the fusiform gyrus and cerebellum. Conclusion Structural and resting-state functional abnormalities in the brain may be useful imaging biomarkers for identifying alterations in trauma-exposed firefighters without PTSD.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3407-3412
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• 2015

Background: The aim of this study was to evaluate and compare the accuracy of diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) value, and time-intensity curve (TIC) type analysis derived from dynamic contrast-enhanced MR imaging (DCE-MRI) in differentiating benign from malignant adnexal masses. Materials and Methods: 47 patients with 56 adnexal masses (27 malignant and 29 benign) underwent DWI and DCE-MRI examinations, prior to surgery. DWI signal intensity, mean ADC value, and TIC type were determined for all the masses. Results: High signal intensity on DWI and type 3 TIC were helpful in differentiating benign from malignant adnexal masses (p<0.001). The mean ADC value was significantly lower in malignant adnexal masses (p<0.001). An ADC value< $1.20{\times}10^{-3}mm^2/s$ may be the optimal cutoff for differentiating between benign and malignant tumors. The negative predictive value for low signal intensity on DWI, and type 1 TIC were 100%. The pairwise comparison among the receiver operating characteristic (ROC) curves showed that the area under the curve (AUC) of TIC was significantly larger than the AUCs of DWI and ADC (p<0.001 for comparison of TIC and DWI, p<0.02 for comparison of TIC and ADC value). Conclusions: DWI, ADC value and TIC type derived from DCE-MRI are all sensitive and relatively specific methods for differentiating benign from malignant adnexal masses. By comparing these functional MR techniques, TIC was found to be more accurate than DWI and ADC.

• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.10-19
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• 2007

Conventional MRI methods using T1-, T2-, diffusion-, perfusion-weighting, and functional imaging rely on characterizing the physical and functional properties of the tissue. In this review, we introduce an imaging modality based on measured the mechanical properties of soft tissue, namely magnetic resonance elastography (MRE). The use of palpation to identify the stiffness of tissue remains a fundamental diagnostic tool. MRE can quantify the stiffness of the tissue thereby providing a objective means to measure the mechanical properties. To accomplish a successful clinical setting using MRE, hardware and software techniques in the area of transducer, pulse sequence, and imaging processing algorithm need to be developed. Transducer, a mechanical vibrator, is the core of MRE application to make wave propagate invivo. For this reason, considerations of the frame of human body, pressure and friction of the interface, and high magnetic field of a MRI system needs to be taken into account when designing a transducer. Given that the wave propagates through human body effectively, developing an appropriate pulse sequence is another important issue in obtaining an optimal image. In this review paper, we introduce the technical aspects needed for MRE experiments and introduce several applications of this new field.

• Journal of Acupuncture Research
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• v.21 no.6
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• pp.177-186
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• 2004

Introduction : Recent studies Suggested that there is a strong correlation between acupuncture stimulation and its related cortical activation. Anther study showed that either positive or negative BOLD effects could be observed depending on anatomical structure in acupuncture stimulation. In ttis study, we investigated a new acupoint $KI_6$ (照海), which was known as motor-related acupoint and obtained an evidence that the stimulation of $KI_6$ resulted in either negative or positive BOLD response to stimulation. Methods & Results : 1. Subjects and paradigms : Two separate stimulation paradigms were performed on five healthy (aged 22-23 yrs) in this study. First, the paradigm of acupuncture stimulation was that the acupuncture needle was inserted in acupoints $KI_6$, which is located in lateral side of the foot and then continuously twisted(補瀉를 除外한 捻轉法) for 70 seconds for 10 cycles of activation. During rest period (70 seconds), the needle was completed removed from acupoint. Total 60 cycles were performed and 10 images were obtained per cycle. Second, nonacupoint was randomly selected and the same paradigm was performed as acupoint stimulation. The stimulation protocol comprised 10 cycles of alternating. activation and rest (10 images per cycle). Total 60 cycles were performed and each cycle take about 1.5 sec for motor task. Subjects take an at least 15 minutes break before starting anther paradigm. 2. fMRI mapping : Multi-slice functional images were obtained on a 1.5T Magnetom Vision MRI scanner (Simens Medical, Erlangen, Germany) equipped with high performance whole-body gradients. The BOLD T2 * - weighted images were acquired with acho planar imaging sequence (TR = 1.2 sec, TE = 60 msec, and flip angle = $90_{\circ}$). The other sequence parameter are : FOV = 210 mm, matrix=$64{\times}128$ or $64{\times}64$, slice number=10 and slice thickness = 5 or 8 mm. the anatomic images were obtained with Spin-echo T1-weighted images. The resulting images were then anaiyzed with STIMULATE (CMRR, U. of Minnesota) to generate functional maps using a student T-test (p < 0.005) and cluster analysis. Both positive and negative response were evaluated. Conclusions : We have observed the activation of the motor cortex by stimulating motor-related acupoint ($KI_6$). Among five subjects, negative BOLD response was shown in four and positive response in one. All subjects showed positive response to conventional finger flexion-extension task. To understand the detailed mechanisms of correlation between acupuncture stimulation and BOLD fMRI changes and two typs of response, further study strongly required.

• Korean Journal of Acupuncture
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• v.21 no.2
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• pp.29-46
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• 2004

Objectives and Methods : This study was performed to investigate the effect of electro -acupuncture at four gates(bilateral LR3 and LI4) on brain activity in normal subjects using fMRI. Results and Conclusions : 1. fMRI signal increase by electro-acupuncture at Lt. LR3 was observed in Rt. Middle frontal gyrus in group average as well as more than half of the subjects. 2. fMRI signal decreases by electro-acupuncture at Lt. LR3 were observed in Rt. Superior frontal gyrus, Rt. Middle temporal gyrus, Rt. Cingulate gyrus in group average as well as more than half of the subjects. 3. fMRI signal increases by electro-acupuncture at Lt. LI4 were observed in Lt. Superior frontal gyrus, Lt. Middle frontal gyrus, Lt. Inf. Semi-Lunar Lobule(cerebellum), Rt. Middle frontal gyrus, Rt. Cingulate gyrus in group average as well as more than half of the subjects. 4. fMRI signal decreases by electro-acupuncture at Lt. LI4 were observed in Lt. Middle frontal gyrus, Lt. Inferior frontal gyrus, Lt. Precentral gyrus and Rt. Middle frontal gyrus, Rt. Middle temporal gyrus, Rt. Precuneus, Rt. Inferior frontal gyrus, Rt. Postcentral gyrus in group average as well as more than half of the subjects. 5. fMRI signal increase by electro-acupuncture at Lt. LR3 and Lt. LI4 in group average as well as more than half of the subjects was not observed. 6. fMRI signal decreases by electro-acupuncture at Lt. LR3 and Lt. LI4 were observed in Lt. culmen(cerebellum), Lt. Cingulate gyrus와 Rt. Middle frontal gyrus, Rt. Cingulate gyrus, Rt. Inferior frontal gyrus in group average as well as more than half of the subjects. 7. fMRI signal increases by electro-acupuncture at four gates (bilateral LR3 and LI4) were observed in Lt. Middle temporal gyrus and Lt. Postcentral gyrus in group average as well as more than half of the subjects. 8. fMRI signal decrease by electro-acupuncture at four gates (bilateral LR3 and LI4) were observed in Lt. Middle frontal gyrus, Lt. Precentral gyrus, Lt. Inferior frontal gyrus, Lt. Middle temporal gyrus, Lt. Frontal sub-gyral and Rt. Tuber(cerebellum) in group average as well as more than half of the subjects.