• The Korean Journal of Pain
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• 제32권4호
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• pp.271-279
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• 2019

Background: We utilized diffusion tensor imaging (DTI) to evaluate the cerebral white matter changes that are associated with phantom limb pain in patients with unilateral arm amputation. It was anticipated that this would complement previous research in which we had shown that changes in cerebral blood volume were associated with the cerebral pain network. Methods: Ten patients with phantom limb pain due to unilateral arm amputation and sixteen healthy age-matched controls were enrolled. The intensity of phantom limb pain was measured by the visual analogue scale (VAS) and depressive mood was assessed by the Hamilton depression rating scale. Diffusion tensor-derived parameters, including fractional anisotropy, mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD), were computed from the DTI. Results: Compared with controls, the cases had alterations in the cerebral white matter as a consequence of phantom limb pain, manifesting a higher AD of white matter in both hemispheres symmetrically after adjusting for individual depressive moods. In addition, there were associations between the RD of white matter and VAS scores primarily in the hemispheres related to the missing hand and in the corpus callosum. Conclusions: The phantom limb pain after unilateral arm amputation induced plasticity in the white matter. We conclude that loss of white matter integrity, particularly in the hemisphere connected with the missing hand, is significantly correlated with phantom limb pain.

• Investigative Magnetic Resonance Imaging
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• 제20권3호
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• pp.141-151
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• 2016

Purpose: Advances of magnetic resonance imaging (MRI), especially that of the Ultra-High Field (UHF) MRI will be reviewed. Materials and Methods: Diffusion MRI data was obtained from a healthy adult young male of age 30 using a 7.0T research MRI scanner (Magnetom, Siemens) with 40 mT/m maximum gradient field. The specific imaging parameters used for the data acquisition were a single shot DW echo planar imaging. Results: Three areas of the imaging experiments are focused on for the study, namely the anatomy, angiography, and tractography. Conclusion: It is envisioned that, in near future, there will be more 7.0T MRIs for brain research and explosive clinical application research will also be developed, for example in the area of connectomics in neuroscience and clinical neurology and neurosurgery.

• The Journal of Korean Physical Therapy
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• 제32권6호
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• pp.388-390
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• 2020

Objectives: The nigrostriatal tract (NST) connect from the substantia nigra pars compacta to the striatum. A few previous studies have reported on the NST in the Parkinson's disease using a proboblistic tractography method. However, no study has been conducted for identification of the NST using streamline DTT technique. In the current study, we used streamline DTI technique to investigate the reconstruction method and characteristics of the NST in normal subjects. Methods: Eleven healthy subjects were recruited in this study. The NST from the substantia nigra of the midbrain and the striatum of basal ganglia was reconstructed using DTI data. Fractional anisotropy, apparent diffusion coefficient (ADC) values and fiber numbers of the NST were measured. Results: In all subjects, the NST between the substantia nigra of the midbrain and the striatum. Mean values for FA, ADC, and tract volume were 0.460, 0.818, and 154.3 in the right NST, and 0.485, 0.818, and 176.3 in the left NST respectively. Conclusions: we reconstructed the NRT from the substantia nigra of the midbrain and the striatum of the basal ganglia using streamline tractography method. We believe that the findings and the proposed streamline reconstruction method of this study would be useful in future researches on the NST of the human brain.

• Investigative Magnetic Resonance Imaging
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• 제17권2호
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• pp.123-132
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• 2013

목적 : 정상인 경수에 대한 내부 부위별, 경수 레벨별 확산텐서영상과 뇌척수액 속도에 대한 정상인 기준을 마련하고자 하였다. 대상 및 방법 : 정상인을 대상으로 3T MRI를 이용하여 영상을 획득하였다. 확산텐서영상은 척수 레벨별로 각각 미리 정의해둔 백질의 후삭, 좌, 우 측삭과 회백질에 관심영역을 정하여 FA, MD에 대한 평균값을 구하였다. PC 기법을 이용한 뇌척수액 속도 측정은 C2-3, C4-5, C5-6 척수레벨을 각각 스캔한 후, 척수 레벨별 최대 수축기 및 이완기 속도를 측정하였다. 결과 : FA 값과 MD 값에서 회백질과 백질의 내부 구조 사이에서는 통계적으로 유의한 차이 (p < 0.05)를 보였다. 경수 레벨별에서는 회백질의 FA 값에서 통계적으로 유의한 차이(p < 0.05)를 보였으며, 나머지 부분에서는 통계적으로 유의한 차이를 보이지 않았다 (p > 0.05). 뇌척수액 속도 측정 결과, 평균 최대 수축기 속도 $5.18{\pm}2.00cm/sec$, 평균 최대 이완기 속도 $-7.32{\pm}3.18cm/sec$ 이었으며, 경수 레벨별로는 통계적으로 유의한 차이를 보이지 않았다 (p > 0.05). 결론 : 정상인에 대한 경수 확산텐서영상의 정량적 수치 및 경수 레벨에 영향을 받지 않는 뇌척수액 속도에 대한 평균치를 알 수가 있었다.

• Korean Journal of Radiology
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• 제23권2호
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• pp.218-225
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• 2022

Objective: This study aimed to explore the feasibility of functional evaluation of the lateral pterygoid muscle (LPM) using diffusion tensor imaging (DTI) in patients with temporomandibular joint disorders (TMDs). Materials and Methods: A total of 119 patients with TMD (23 male and 96 female; mean age ± standard deviation, 41 ± 15 years; 58 bilateral and 61 unilateral involvements for a total of 177 joints) and 20 healthy volunteers (9 male and 11 female; 40 ± 13 years; 40 joints) were included in this prospective study. Based on DTI of the jaw in the resting state, the diffusion parameters, apparent diffusion coefficient (ADC), fractional anisotropy (FA), λ1, λ2, and λ3 of the superior and inferior heads of the LPM (SHLPM and IHLPM) were measured. Patients with TMD with normal disc position (ND), anterior disc displacement with reduction (ADWR), and anterior disc displacement without reduction (ADWOR) were compared. Results: Patients with TMD overall, and ADWR and ADWOR subgroups had significantly higher ADC, λ1, λ2, and λ3 in both the SHLPM and IHLPM than those in volunteers (p < 0.05 for all), whereas the ND subgroup only had significantly higher ADC and λ1 (p < 0.001). Meanwhile, significant differences in FA in the SHLPM and IHLPM were found between volunteers and ADWOR (p = 0.014 and p = 0.037, respectively). Among the three TMD subgroups, except for λ3 and FA in the ADWR subgroup, ADWR and ADWOR subgroups had significantly higher ADC, λ1, λ2, and λ3 and lower FA than those in the ND group (p < 0.050). There was no significant difference in diffusion variables between ADWR and ADWOR. In ADWOR, the osteoarthritis group had significantly higher λ3 and lower FA values in the IHLPM than those in the non-osteoarthritis group. Conclusion: DTI successfully detected functional changes in the LPM in patients with TMD. The unsynchronized diffusivity changes in the LPM in different subgroups of TMD signified the possibility of using diffusion parameters as indicators to identify the severity of LPM hyperfunction at various stages of TMD.

• PNF and Movement
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• 제14권1호
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• pp.41-47
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• 2016

Purpose: In general, confabulation is defined as confusion of reality with past events without apparent prompting, in association with disruption of the capacity for retrieval and encoding of memory. We report on a patient who showed spontaneous confabulation associated with injury of the Papez circuit following middle cerebral artery (MCA) infarction. Methods: A 67-year-old female patient suffered cerebral infarct resulting from spontaneous MCA territory. After onset of the MCA infarct, she showed severe memory impairment and provoked confabulation. The Papez circuit was reconstructed for evaluation of part of it using diffusion tensor tractography (DTT). Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured. Results: The right thalamocingulate tract showed a significant decrement of FA value and tract volume, and an increment of MD value by more than two standard deviations of that of normal control subjects. The tract volume in the left fornix and mammillothalamic tract decreased by more than two standard deviations of that of normal control subjects. Conclusion: Injuries of the Papez circuit were demonstrated in a patient who showed severe memory impairment and provoked confabulation following MCA infarct. We believe that analysis of the Papez circuit tract using DTT is useful in elucidating the cause of provoked confabulation in patients with MCA infarct.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.49-53
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• 2003

확산텐서영상(Diffusion Tensor Imaging)의 개념은 1980년대 중반 확산강조영상(Diffusion Weighted Imaging)의 개념이 도입되면서 거의 동시에 도입되었지만 MR 장비의 기계적 한계등으로 인해 최근에야 임상적으로 사용되기 시작했다. 확산텐서영상(DTI)과 확산강조영상(DWI)의 방법론적인 차이점은 단순히 확산강조영상의 경우 세 개의 다른방향 (X-, Y-, Z-축)으로 확산측정용 경사자장을 가하는 반면 확산텐서영상의 경우 이보다 많은 방향 (최소한 6 방향)으로 확산측정용 경사자장을 가한다는 점이다. 이러한 차이로부터 금방 알 수 있는 점은 확산강조영상은 확산텐서영상의 일부라는 점이다. 즉, 확산텐서영상의 경우 더 많은 방향으로 확산측정용 경사자장을 가했으므로 더 많은 정보를 획득할 수 있고 이중 세 개의 방향 (주로 X,Y,Z)에 대한 정보만을 이용하게 되면 확산강조영상이다. 이러한 이유로 확산텐서영상을 획득하면 확산강조영상에서 얻게 되는 방향별 확산강조영상, 등방성(isotropic) 확산강조영상, ADC (Apparent Diffusion Coefficient) map등도 기본적으로 얻게 되므로 추가로 확산강조영상을 획득할 필요가 없다. 본 강의에서는 이러한 확산(텐서)영상의 물리적 원리를 복잡한 수학적 설명보다는 개념 위주로 설명해 보고자 한다.

• Journal of Korean Neurosurgical Society
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• 제56권1호
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• pp.11-15
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• 2014

Objective : Facial nerve palsy is a common complication of treatment for vestibular schwannoma (VS), so preserving facial nerve function is important. The preoperative visualization of the course of facial nerve in relation to VS could help prevent injury to the nerve during the surgery. In this study, we evaluate the accuracy of diffusion tensor tractography (DTT) for preoperative identification of facial nerve. Methods : We prospectively collected data from 11 patients with VS, who underwent preoperative DTT for facial nerve. Imaging results were correlated with intraoperative findings. Postoperative DTT was performed at postoperative 3 month. Facial nerve function was clinically evaluated according to the House-Brackmann (HB) facial nerve grading system. Results : Facial nerve courses on preoperative tractography were entirely correlated with intraoperative findings in all patients. Facial nerve was located on the anterior of the tumor surface in 5 cases, on anteroinferior in 3 cases, on anterosuperior in 2 cases, and on posteroinferior in 1 case. In postoperative facial nerve tractography, preservation of facial nerve was confirmed in all patients. No patient had severe facial paralysis at postoperative one year. Conclusion : This study shows that DTT for preoperative identification of facial nerve in VS surgery could be a very accurate and useful radiological method and could help to improve facial nerve preservation.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회.한국자기공명학회 2005년도 공동학술대회
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• pp.26-26
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• 2005

• The Journal of Korean Physical Therapy
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• 제22권5호
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• pp.109-115
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• 2010

Purpose: This study was to delineate the structural change of neural pathway after sequential motor learning using diffusion tensor imaging (DTI). Methods: The participants were 16 healthy subjects, which were divided by training (n=8) and control (n=8) group. The task for the training was the Serial Reaction Time Task (SRTT) which was designed by Superlab program. When the 'asterisk' shows up in the 4 partition spaces on the monitor, the subject presses the correct response button as soon as possible. The training group participated in the training program of motor learning with SRTT composed of 24 digits pattern in one hour per daily through 10 days during 2 weeks. Results: In the behavioral results the training group showed significant changes in the increase of response number and the reduction of response time than those of the control group. There was significant difference in the left inferior frontal area in the fractional anisotropy (FA) map of the training group in DTI analysis. Conclusion: Motor sequential learning as like SRTT may be needed to the learning of language and visuospatial processing and may be induced for the experience-dependent structural plasticity during short period.