• Journal of Korean Neurosurgical Society
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• 제45권1호
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• pp.1-4
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• 2009

Objective : In the present study, the authors investigated the clinical and imaging features as well as the therapeutic outcomes of SIH (spontaneous intracranial hypotension) patients. Methods : A retrospective review of 12 SIH patients was carried out. The diagnostic work-up included lumbar tapping and measurement of CSF opening pressure, radioisotope cisternography, brain and spinal magnetic resonance imaging (MRI), and computed tomography (CT) myelography. Autologous epidural blood patching was performed in patients who did not respond to conservative therapies, including analgesics, steroids, hydration and rest. Results : Typical postural headache was found in 11 (91%) patients. Nine (75%) patients showed pachymeningeal enhancement on their initial T1-weighted MR images. The CSF opening pressure was less than 60 mm$H_2O$ in 9 of 11 patients. Autologous epidural blood patching was performed in 7 patients, and all of them showed good responses. Conclusion : SIH can present with various clinical presentations and neuroimaging findings. Autologous epidural blood patching is thought to be the treatment of choice for patients with SIH.

• 한국전자파학회논문지
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• 제9권6호
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• pp.776-787
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• 1998

835 MHz에서 동작하는 셀룰라 휴대폰에 의한 인체 두부내의 1 g 및 10 g 평균 비홉수율(specific absorption rate, SAR)을 해석한다. 사용되는 수치방법은 총 전자기장 유한차분 시간영역(finite-difference time-domain, FDTD) 기법이다. 전화기는 도체박스, 플라스틱 케이스 그리고 모노폴 안테나와 나선형 안테나 로 구성된 whip 안테나로 모의되었다. 공간 정밀도 3 mm의 이산적 인체두부 모델은 MRI(Magnetic Resonance Imaging), CT(computerized tomography) 그리고 해부학적 이미지에 기초한 것이다 안테나를 뽑은 전화기와 접은 전화기에 대한 근역장 및 원역장 복사 패턴이 분석되었다. SAR 평가를 위한 재현성 있는 기법을 제공하기 위해 조직내의 1 g 또는 10 g의 질량을 갖는 체적을 취하는 두 가지 방법을 제안하고 비교 한다.

• 대한의생명과학회지
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• 제11권2호
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• pp.221-225
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• 2005

To investigate the spectroscopic findings of embolized lesions induced with a fat-emulsion technique with magnetic resonance images (MRI). A fat emulsion was made with 0.1 ml of triolein and 20 ml of normal saline. In 12 cats, the internal carotid artery was infused with the fat emulsion. Contrast-enhanced T1-weighted MRI and multivoxel spectroscopy were obtained at 1 hour, 1 and 4 days, and 1 week after embolization. NAA (N-acetylaspartate), Cr (creatine) and Cho (choline) were evaluated on the spectroscopy. Statitistical analysis wsperformed at the embolized and contralateral normal hemisphere in the integral and amplitude of NAA, Cr and Nho in time course. Also NAA/Cr and Cho/Cr were compared in both hemisphere and in time course. The emboli zed lesions showed contrast enhance ments on Gd-enhanced Tl-weighted i~ages at 1 hour. This contrast enhancement was decreased at day 1, and id not appear agter day 4. In spectroscopy, the embolized hemisphere showed no statistical difference to the normal contralateral side at 1 hour and in time course. NAA/Cr and Cho/Cr were not significantly different in both hemispheres at 1 hour and in time course. Cerebral-fat embolism induced by a triolein emulsion in cats revealed no statistical difference on MR spectroscopy. Triolein-emulsion can be used in the study of blood-brain barrier.

• 대한족부족관절학회지
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• 제13권1호
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• pp.19-22
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• 2009

Purpose: This retrospective study was designed to determine the type and frequency of associated lesions in patients with chronic lateral ankle instability who had modified Brostrom lateral ankle ligament reconstruction. Materials and Methods: Between 2004 and 2007, 60 cases of 60 patients were enrolled in this study. A retrospective review of the magnetic resonance images of the affected ankle was conducted by two orthopedic surgeons who did not get any information about intraoperative findings and the lesions were admitted when two doctors were coincident. Results: The overall incidence of associated lesions found in this study was about 83%. Peroneal tenosynovitis was the highest frequency (32%), followed by osteochondral lesion of talus (28%), anterolateral impingement (15%), Os subfibula (13%), Os trigonum (12%), ankle synovitis (12%), anterior tibiofibular ligament tear (15%), anterior bony spur (7%). Another findings were loose bodies (5%), flexor tendon tenosynovitis (5%), medial osteophyte (3%). Conclusion: Identifying these associated lesions will be helpful in treating chronic lateral ankle instability especially when the surgeon have a plan to operate the instability. We suggest that the better results can be obtained when the associated lesions are corrected simultaneously.

• 한국임상수의학회지
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• 제33권6호
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• pp.389-391
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• 2016

A 10-month-old, intact female Shih-tzu dog with a pelvic limb ataxic gait, and urinary and fecal incontinence since birth, was examined by computed tomography and magnetic resonance imaging. The butterfly hemivertebra of the fourth lumbar vertebra, agenesis of the third sacral and coccygeal vertebrae, and spina bifida of the remaining sacral vertebra were observed on the computed tomography images. Magnetic resonance imaging revealed traction of the conus medullaris. The dog was diagnosed with sacrocaudal dysgenesis with presumptive tethered cord syndrome, and concurrent infectious cystitis was found by ultrasonography and urinary analysis. The Shih-tzu recovered from the cystitis, but still has the ataxic gait and urinary and fecal incontinence. This report summarizes the case of a dog with sacrocaudal dysgenesis that was identified by imaging diagnosis.

• 대한한방내과학회지
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• 제39권5호
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• pp.863-869
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• 2018

Objectives: The purpose of this case study was to report the effectiveness of Korean medicine treatment on severe lumbar disc herniation patient diagnosed by magnetic resonance imaging (MRI). Methods: The patient was treated with complex Korean medicine treatment, including acupuncture, pharmacopuncture, acupotomy, and Chu-na treatment. The treatment effect was evaluated by a Numerical Rating Scale (NRS), and MRI. Results: After the treatment, the NRS score of pain intensity was reduced from severe to mild degree. The volume of extruded disc in MRI images was clearly reduced. Conclusion: Korean medicine treatment might be effective in patients with lumbar disc herniation.

• Imaging Science in Dentistry
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• 제33권2호
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• pp.63-70
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• 2003

Purpose: To describe the MRI findings of the retrodiskal tissue in patients presenting with TMJ internal derangement and to correlate these findings with clinical and other MRI manifestations. Materials and Methods: One hundred eighteen joints of 63 patients with TMJ internal derangement were examined by MRI. Tl-weighted sagittal MR images taken in both closed- and open-mouth were evaluated for the presence of demarcation between disk and retrodiskal tissue, the presence of low signal intensity, and the depiction of the temporal part of the posterior attachment. The results were correlated with the duration of TMJ internal derangement, the presence of pain, and other MRI findings, including the type of internal derangement, the extent of disk displacement, the degree of disc deformation, and the presence of osteoarthrosis. Results: A significant relationship between the presence of low signal intensity in the retrodiskal tissue and other MRI findings was determined. Low signal intensity on the open-mouth view was observed more frequently in patients with disc displacement without reduction, severe disc displacement and deformation, and osteoarthrosis (p<0.05). The demarcation between disk and retrodiskal tissue, and the depiction of the temporal part of the posterior attachment(TPA) were correlated neither with clinical, nor with other MRI findings. Conclusion: This study suggests that low signal intensity in the retrodiskal tissue on open-mouth MR image can be indicative of advanced stages of disk displacement.

• Investigative Magnetic Resonance Imaging
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• 제13권1호
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• pp.1-8
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• 2009

유방 MRI는 유방 질환의 진단과 치료 분야에 최첨단 기법으로서 지난 10년 동안 유방 MRI는 연구 분야에서 임상 분야로 진화해 왔다. 따라서, 유방 MRI의 적응증과 적절한 영상을 얻는 방법, 소견을 해석하고 보고하는 법에 대한 이해가 필요하다. 유방 MRI는 양성과 악성 종괴의 감별, 유방암 환자의 수술 전 병기 결정, 수술전 항암요법에 대한 종양의 반응 평가, 유방 성형 여성의 평가 등에 사용되고 있다. 또한 유방암 고위험군 여성에서 선별 보조 검사로서 사용될 수 있다. 이러한 목적을 성공적으로 이루기 위해서는 적절한 MRI기법과 다른 유방 영상 소견과 연관 지어 해석할 수 있는 영상의학과 의사가 중요하다. 본 소고에서는 유방 MRI의 적응증, 표준화된 용어와 카테고리의 사용에 중점을 두어 기술하고자 한다.

• 한국소음진동공학회논문집
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• 제24권1호
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• pp.62-68
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• 2014

Recently, MRI(magnetic resonance imager) scanner is continually used for medical diagnosis and many biomedical researches. When it operates, however, intense noise is generated. The SPL(sound pressure level) of the noise approaches 130 dB especially in 3 T(Tesla) MRI. Meanwhile, more than 3 T MRI scanners have been developed to get higher-resolution images, so louder noise is expected in the future. The intense noise makes patients feel nervous and uncomfortable. Moreover, it could possibly cause hearing loss to patient in extreme cases. For this reason, some active noise control systems have been researched. One of them used feedback Filtered-X LMS(FXLMS) algorithm which is able to control only narrowband noises and possible to diverge in severe case. In this paper, we determine the property of MRI noise. Using the property, we applied a method of open-loop and adaptive control for reducing MRI noise at target point inside bore. We verified performance of the method with computer simulation and preliminary experiment. The results demonstrate that the method can effectively reduce MRI noise at target point.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1236-1247
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• 2016

Recently, the level set has become a popular method in many research fields. The main reason is that it can be modified into many variants. One such case is our proposed method. We describe a contrast-enhancement method to segment the hippocampal region from the background. However, the hippocampus region has quite similar intensities to the neighboring pixel intensities. In addition, to handle the inhomogeneous intensities of the hippocampus, we used a bias correction before hippocampal segmentation. Thus, we developed a contrast-enhanced bias-corrected distance-regularized level set (CBDLS) to segment the hippocampus in magnetic resonance imaging (MRI). It shows better performance than the distance-regularized level set evolution (DLS) and bias-corrected distance-regularized level set (BDLS) methods in 33 MRI images of one normal patient. Segmentation after contrast enhancement and bias correction can be done more accurately than segmentation while not using a bias-correction method and without contrast enhancement.