• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.1
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• pp.1-11
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• 2013

The determination of the pose of the imaging camera is a fundamental problem in computer vision. In the monocular case, difficulties in determining the scene scale and the limitation to bearing-only measurements increase the difficulty in estimating camera pose accurately. Many mobile phones now contain inertial measurement devices, which may lend some aid to the task of determining camera pose. In this study, by means of simulation and real-world experimentation, we explore an approach to monocular camera localization that incorporates both observations of the environment and measurements from accelerometers and gyroscopes. The unscented Kalman filter was implemented for this task. Our main contribution is a novel approach to landmark initialization in a Kalman filter; we characterize the tolerance to noise that this approach allows.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.505-510
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• 2009

The possible causes of Brown-S$\acute{e}$quard Syndrome (BSS) have been frequently observed with spinal trauma and extramedullary spinal tumors, but the cervical disc herniation to cause BSS is rare. The authors present five cases of patients who were diagnosed with BSS resulting from cervical disc herniation, and the results of the literature in view of their distinctive symptoms and clinical outcomes. Postoperatively, the patients showed complete or almost complete recovery from their motor and sensory deficits. On the basis of our cases, it is important to diagnose it early by cervical magnetic resonance imaging, especially in the absence of the typical symptoms of cervical disc herniation or other obvious etiology of extremity numbness. Immediate surgical treatment is also essential for a favorable functional neurological recovery.

• ETRI Journal
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• v.31 no.4
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• pp.448-450
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• 2009

In multiview imaging systems, color correction is adopted to eliminate color inconsistency between views. However, the influence of highlights on color correction has not been considered before. In this letter, a new color correction method based on highlight detection is proposed. The method is designed to treat highlight and highlight-removal regions independently when calculating correction parameters. Finial correction is implemented with a fusion mechanism. Experimental results show that the proposed method can improve objective and subjective correction performance, while achieving better coding performance than other correction methods.

• Journal of Korean Neurosurgical Society
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• v.54 no.2
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• pp.145-147
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• 2013

We present a case of acute hydrocephalus secondary to cervical spinal cord injury in a patient with diffuse ossification of the posterior longitudinal ligament (OPLL). A 75-year-old male patient visited the emergency department with tetraparesis and spinal shock. Imaging studies showed cervical spinal cord injury with hemorrhage and diffuse OPLL from C1 to C4. We performed decompressive laminectomy and occipitocervical fusion. Two days after surgery, his mental status had deteriorated to drowsiness with dilatation of the right pupil. Findings on brain computed tomography revealed acute hydrocephalus and subarachnoid hemorrhage in the cerebellomedullary cistern, therefore, extraventricular drainage was performed immediately. Acute hydrocephalus as a complication of cervical spine trauma is rare, however, it should be considered if the patient shows deterioration of neurologic symptoms.

• Journal of Korean Neurosurgical Society
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• v.48 no.6
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• pp.541-543
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• 2010

The purpose of this case report is to describe a rare case of a cervicothoracic spinal epidural hematoma (SEH) after anterior cervical spine surgery. A 60-year-old man complained of severe neck and arm pain 4 hours after anterior cervical discectomy and fusion at the C5-6 level. Magnetic resonance imaging revealed a postoperative SEH extending from C1 to T4. Direct hemostasis and drainage of loculated hematoma at the C5-6 level completely improved the patient's condition. When a patient complains of severe neck and/or arm pain after anterior cervical spinal surgery, though rare, the possibility of a postoperative SEH extending to non-decompressed, adjacent levels should be considered as with our case.

• Journal of Trauma and Injury
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• v.35 no.2
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• pp.115-117
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• 2022

"Whiplash"-type injuries are commonly encountered and often cause neck pain, neck stiffness, and headaches. However, these injuries can have rare and poorly recognized complications, such as the development of a prevertebral hematoma leading to acute respiratory failure in the emergency department, followed by severe, life-threatening dysphagia and recurrent aspirations. In the patient described herein, a whiplash injury was accompanied by vocal cord paralysis and dysphonia (vagus nerve), dysgeusia (glossopharyngeal nerve, vagus nerve), and upper esophageal spasm (cricopharyngeal muscle, vagus nerve). It is unlikely that this was a complication of cervical fusion surgery. Instead, a combined stretch-induced lower cranial nerve injury, possibly on the exit of these nerves through the jugular foramen, seems to be a likely, but underappreciated mechanism occurring in rare instances of whiplash injuries.

• Annual Conference of KIPS
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• 2022.11a
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• pp.292-294
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• 2022

본 논문은 3 차원 이미징 기술과 컴퓨터 그래픽스 기반의 시뮬레이션 분야에서 매우 성공적인 두 기술의 융합을 기반으로 진행한 연구를 제안한다. 먼저 3 차원 디스플레이 시스템에 재생할 집적 영상 이미지를 생성하는 방법에 대해 설명한다. 이는 3 차원 포인트 클라우드에서 가상 핀홀 배열로 입사각을 역투영하는 계산방식을 통해 해당 이미지를 생성한다. 우리는 재생되는 3 차원 영상의 초점면을 자유롭게 선택하는 방법에 대해서도 설명한다. 또한, 복수의 관찰자에게 동시에 다양한 시점 정보를 기반으로 몰입감 넘치는 3 차원 영상을 제공하는 3 차원 디스플레이 시스템을 소개하고, 다양한 실험결과를 기반으로 결론을 제시한다.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.3
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• pp.331-337
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• 2024

This is a unique case of metastatic pheochromocytoma of the cervical spine treated with preoperative embolization and subsequent en bloc resection. A 65-year-old man with metastatic pheochromocytoma presented with two weeks of worsening neck pain, left arm and leg weakness and paresthesia, and urinary incontinence. Magnetic resonance imaging showed a metastatic osseous lesion at C6 with severe stenosis and spinal cord compression. The patient underwent successful preoperative angiographic embolization with a liquid embolic agent followed by C5-C7 laminectomy, en bloc tumor resection, and C3-T2 posterior spinal fusion. Six weeks postoperatively, the patient reported improving strength and resolving neck pain and paresthesias. While there is no standard paradigm for the treatment of metastatic pheochromocytomas of the cervical spine, preoperative embolization may minimize intraoperative blood loss and hemodynamic instability during subsequent surgical resection.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.23-27
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• 2006

Purpose: There are a few case reports on asymmetric vocal cord uptake on FDG-PET in patients with unilateral vocal cord paralysis, which could be a potential pitfall in the interpretation of FDG-PET images. We evaluated the metabolic activity of laryngeal muscles of patients with unilateral vocal cord paralysis in comparison to normal controls during both speech and silence. Methods: Eleven patients with unilateral vocal cord palsy (thyroldectomy=7, lung cancer=1, others=3) and 12 normal controls underwent FDG-PET with usual protocol. They were divided into two groups respectively; one group read books aloud for 20 minutes (phonation group) and the other kept silence (non-phonation groups) after FDG injection. Recent neck CT scan were co-registered with FDG-PET to produce PET-CT fusion images to elaborate small laryngeal muscles. Results: In patients with unilateral vocal cord palsy, contralateral non-paralyzed vocal cord showed hypermetabolism mainly on thyroarytenoid muscle, more intensely with phonation group ($SUV=5.88{\pm}2.65$) than with non-phonation group ($SUV=2.30{\pm}0.39$). Normal control subjects showed hypermetabolism ($3.68{\pm}0.96$) in interarytenoid muscle and symmetric mild hypermetabolism in both lateral cricoarytenoid muscles in only phonation group. Conclusion: FDG-PET with fusion images using CT scan in patients with unilateral vocal cord paralysis showed hypermetabolism of contralateral non-paralyzed thyroarytenoid muscle, suggesting compensatory action during phonation. Phonation durung FDG PET study enhanced FDG uptake on different laryngeal muscles between patients with unilateral vocal cord paralysis and normal subjects.

• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.112-117
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• 1999

Background : Posterior tibial nerve somatosensory evoked potentials (PTSEP) have cortical potentials on primary sensory area of foot around 40 msec. The direct cortical recordings of the cortical potentials shows high voltage positive wave on medial hemisphere, especially on paracentral lobule (PCL). However, it is so difficult to record the potential directly on PCL that the cortical potential of PTSEP is not well understood. We investigated the cortical potential of PTSEP on subdural electrodes. Methods : We recorded cortical potentials to posterior tibial nerve stimulation on subdural electrodes which were on medial hemisphere near PCL in 15 intractable neocortical epilepsy patients. The numbers of subdural electrodes were 8 in 10 subjects ($1{\times}8array$) and 16 in 5 subjects ($2{\times}8arrays$). Seven subjects had three-dimensional imaging fusion (3D-fusion) of MRI and the electrodes using Analyze program. We investigated the amplitude, latency, polarity, and phase of the waves regarding location. Results : The waves had maximal amplitude on PCL in 4 subjects, precuneus in 1, cingulate gyrus nearest to PCL in 2 among 7 subjects with 3D-fusion. Also the electrodes were located on posterior area of PCL (2 out of 2 subjects with more than two electrodes put on PCL in 3D-fusion) and superior area of it (5 out of 5 subjects with $2{\times}8arrays $). All the high (more than 20 uV) amplitude around 40msec had positive polarity in 7 subjects. The phase reversals were detected between the electrodes with the highest amplitude and the just posterior (2 subjects) or anterior (6 subjects) located electrodes. The just posterior located electrodes had sharper phase reversal than the anterior one. Conclusion : PTSEP might have maximal amplitude of cortical potentials on the more superior and posterior area of PCL. The highest amplitude potential has positivity. The wave with maximal amplitude could have phase reversal of cortical potentials with surrounding electrodes, especially shaper with posterior part than with anterior one.