• Journal of Science and Technology Studies
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• v.14 no.2
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• pp.199-222
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• 2014

Functional Magnetic Resonance Angiography (fMRA) was a technoscientific innovation that allows scientists to directly view the changes made in the blood vessels of a brain. fMRA was first developed at Neuroscience Research Institute (NRI) in Korea. fMRA mainly utilizes 7 Tesla MRI technology, and NRI is equipped with the instrument. First article on fMRA was published in 2008, and two more papers in 2010 and 2012 consecutively had been published on the newly developed technique. However, fMRA is a competitive technology with existing fMRI. Both techniques capture microvascular changes in a brain, and by doing it, both techniques visualize the cognitive and affective changes. fMRI technology was introduced by Seiji Ogawa in the early 1990's and has been widely used since then. In contrast, fMRA was a newer technology and rather unknown. Developers of fMRA in NRI used series of signifiant-politics in order to make it better known to scientific community as well as public. By resetting the boundaries of existing concept of fMRI, they tried to lower the threshold of a new concept/technique. This case study shows how technoscientists use semiotic strategies governing new technology.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.29-35
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• 2021

The purpose of this study was to investigate whether there is a difference in image quality before and after reducing the amount of contrast medium in cerebral hemorrhagic patients who periodically follow up CT, and after reducing the amount of contrast medium, the image before and after reduction was examined, and the image quality was assessed by setting ROI at each vessel location using MMWP program. First Rt. CCA, Lt.CCA. Rt.MCA, Lt.MCA and Basilar Artery each got an ROI. Second, the mean and standard deviation values for the ROI were obtained. Third, SNR and CNR were obtained through the average and standard deviation values obtained. T-test statistics show that the SNR and CNR values obtained show that the result values for SNR are Rt.CCA 0.765, Ltd.CCA 0.871, Rt.MCA 0.343 LT.MCA 0.235, Basilar alternative 0.916, result value for CNR Rt.CCA 0.088, Ltd.CCA 0.069, Rt.MCA 0.818, Let's...MCA 0.579 and Basilar Artery 0.878. The results obtained through the obtained SNR and CNR values showed no difference in the quality of the images before and after reducing contrast medium. Therefore, we hope that this study will be an indicator that reduces the burden on contrast agents on patients who do CT examinations periodically.

• Journal of Trauma and Injury
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• v.28 no.3
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• pp.190-194
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• 2015

Blunt cerebrovascular injury is defined as a vertebral or carotid arterial structural wall injury resulting from nonpenetrating trauma. Complete traumatic internal carotid artery occlusion is very rare condition accounting for 0.08~0.4 0f all trauma patients and believed to be associated with the greatest risk of ischemic stroke reported in 50~90% in a few small series. A 55-year-male was admitted with drowsy mentality and severe headache after a fall down accident. Brain computed tomography showed a subdural hematoma at the both frontal area with a fracture of the occipital skull bone. Two days after admission, he suddenly complained with a right side hemiparesis of motor grade 2. Brain magnetic resonance diffusion demonstrated multiple high flow signal changes from the left frontal and parietal lesion. Computed tomographic angiogram (CTA) revealed absence of the left ICA flow. Trans femoral cerebral angiography (TFCA) showed complete occlusion of the left internal carotid artery (ICA) at ophthalmic segment in the left ICA angiogram and flows on the left whole hemispheric lesions through the anterior communicating artery in the right ICA angiogram. We decided to conduct close observations as a treatment for the patient because of acute subdural hematoma and sufficient contralateral cerebral flow by perfusion SPECT scan. Two weeks after the accident, he was treated with heparin anticoagulation within INR 2~4 ranges. He recovered as the motor grade 4 without another neurologic deficit after 3 months.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.527-530
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• 2014

Spinal subarachnoid hemorrhages (SAH) can extend into the intracranial subarachnoid space, but, severe cerebral vasospasm is rare complication of the extension of intracranial SAH from a spinal subarachnoid hematoma. A 67-year-old woman started anticoagulant therapy for unstable angina. The next day, she developed severe back pain and paraplegia. MRI showed intradural and extramedullar low signal intensity at the T2-3, consistent with intradural hematoma. High signal intensity was also noted in the spinal cord from C5 to T4. We removed subarachnoid hematoma compressing the spinal cord. The following day, the patient complained of severe headache. Brain CT revealed SAH around both parietal lobes. Three days later, her consciousness decreased and left hemiplegia also developed. Brain MRI demonstrated multiple cerebral infarctions, mainly in the right posterior cerebral artery territory, left parietal lobe and right watershed area. Conventional cerebral angiography confirmed diffuse severe vasospasm of the cerebral arteries. After intensive care for a month, the patient was transferred to the rehabilitation department. After 6 months, neurologic deterioration improved partially. We speculate that surgeons should anticipate possible delayed neurological complications due to cerebral vasospasm if intracranial SAH is detected after spinal subarachnoid hematoma.

• Investigative Magnetic Resonance Imaging
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• v.9 no.2
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• pp.94-100
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• 2005

Purpose : This study was designed to evaluate the usefulness of 3T-TOF MR angiography (3T-TOF MRA) compared with transcranial Doppler sonography (TCD) and conventional angiography (CA) in patients with suspected cerebral infarction. Materials and Methods : Fifty four patients with clinical symptoms of cerebral infarction were involved in this study, and had undergone 3T-TOF MRA and TCD, with CA in 11 patients. On the basis of divisions of the carotid artery, four groups were designated: group I, both vertebral arteries and basilar artery; group II, segment between 2 cm below bifurcation of common carotid artery and genu portion of internal carotid artery; group III, segment between petrous portion of internal carotid artery and bifurcation of anterior and middle cerebral artery; group IV, from bifurcation of anterior and middle cerebral artery to thier distal branches. Two radiologists retrospectively reviewed the vascular imaging and stenosis in 3T-TOF MRA, TCD, and CA. Results : A total of 432 arteries, 108 in each group, were available. The assessment of vascular imaging quality in 3T-TOF MRA is scored 2.98, 2.96, 2.91, 2.88 in 4 groups, respectively. Agreement among 3T-TOF MR angiography, TCD, and CA was high. Conclusion : 3T-TOF MR angiography may be useful method for the assessment of stenotic lesions of cranial vasculature in patients with cerebral infarction.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.101-106
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• 2004

In this paper, a blood vessel in an angiographic image, which plays an importance role in the diagnose diseases including in the eyes, brain and heart, is enhanced by using a directed diffusion technique. A fundamental component of the angiographic analysis is vessel segmentation that the proposed method provides a preprocessing of the image into a form suitable for human analysis, or more importantly, for machine analysis such the segmentation. Vessel enhancement is a challenging problem due to the complex nature of vascular trees and to imaging imperfections. Some parts of the inherent imperfections in angiography are the intensity inhomogeneity between the larger and smaller vessels, and another imperfection is the leakage of contrast agent into the background tissue that provides to low contrast between vessels and tissue. In the proposed scheme, the directed diffusion solves the problem by formulating a local geometric structure, which consists of direction and scale of the blood vessels. The diffusion process uses the local structure to enhance by a diffusivity tensor. The proposed algorithm can be applied to maintain sharpness and coherence-smooth the intra-regions into homogeneity better than traditional diffusion methods, which are Gaussian regulation and coherence enhancing diffusion.

• Archives of Craniofacial Surgery
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• v.11 no.2
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• pp.116-119
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• 2010

Purpose: Arteriovenous fistulas that involve the cavernous sinus often produce ophthalmologic symptoms and signs. Transvenous endovascular access is the method of choice for a carotid-cavernous sinus fistula. The superior ophthalmic vein is a safe and reasonable alternative route for the transvenous embolization of carotid-cavernous sinus fistula. We report a case of the embolization of a carotid-cavernous sinus fistula using the superior ophthalmic vein approach. Methods: A 58 year old female had conjunctival congestion, periocular pain and diplopia with a 2 month duration. Diagnostic orbital CT, brain MRI and cerebral angiography revealed a carotid-cavernous sinus fistula. The fistula occlusion was treated by coil embolization using the superior ophthalmic vein approach. Results: The initial presenting symptoms, conjunctival congestion, periocular pain and diplopia, decreased after surgery. Coil embolization via the superior ophthalmic vein approach was difficult because of the venous tortuosity and friability. During the follow up period, the patient was in a good condition without complications. Conclusion: Surgical exposure of the superior ophthalmic vein provides direct venous access to the cavernous sinus as well as an effective and safe treatment approach. The cooperation of the plastic surgeon and interventionist is a factor in successful treatment.

• Journal of Korean Neurosurgical Society
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• v.29 no.2
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• pp.265-269
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• 2000

Traumatic aneurysm is a rare complication of head trauma. Unfortunately, it is rarely recognized until their presence is heralded by delayed deterioration or intracranial hematoma, etc,. Early diagnosis and surgical treatment are most important for good outcome. We recently encountered a patient who developed a pericallosal aneurysm after major trauma. With a high index of suspicion about traumatic aneurysm, brain MRI and MRA were performed. Definitive diagnosis was made by transfemoral carotid angiography, revealing a aneurysm of the right proximal pericallosal artery. The aneurysm was explored through right interhemispheric approch. A $15{\times}15mm$ sized traumatic aneurysmal sac, located in proximal portion of right pericallosal artery was noted. It was dissected from the falx of cerebri and its neck was clipped. The postoperative course was uneventful. Traumatic intracranial aneurysm should be suspected in any patient who deteriorates after the trauma. Early recognition and prompt treatment are warranted in this setting. Definitive surgical treatment of all traumatic intracranial aneurysm is recommended.

• Journal of Korean Neurosurgical Society
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• v.58 no.3
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• pp.291-293
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• 2015

Anterior communicating artery (ACoA) aneurysms sometimes present with visual symptoms when they rupture or directly compress the optic nerve. Giant or large ACoA aneurysms producing bitemporal hemianopsia are extremely rare. Here we present an unusual case of bitemporal hemianopsia caused by a large intracranial aneurysm of the ACoA. A 41-year-old woman was admitted to our neurosurgical department with a sudden-onset bursting headache and visual impairment. On admission, her vision was decreased to finger counting at 30 cm in the left eye and 50 cm in the right eye, and a severe bitemporal hemianopsia was demonstrated on visual field testing. A brain computed tomography scan revealed a subarachnoid hemorrhage at the basal cistern, and conventional cerebral catheter angiography of the left internal carotid artery demonstrated an $18{\times}8mm$ dumbbell-shaped aneurysm at the ACoA. Microscopic aneurysmal clipping was performed. An ACoA aneurysm can produce visual field defects by compressing the optic chiasm or nerves. We emphasize that it is important to diagnose an aneurysm through cerebrovascular study to prevent confusing it with pituitary apoplexy.

• Journal of Korean Neurosurgical Society
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• v.56 no.2
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• pp.141-145
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• 2014

Vertebral artery (VA) injuries usually accompany cervical trauma. Although these injuries are commonly asymptomatic, some result in vertebrobasilar infarction. The symptoms of VA occlusion have been reported to usually manifest within 24 hours after trauma. The symptoms of bilateral VA occlusions seem to be more severe and seem to occur with shorter latencies than those of unilateral occlusions. A 48-year-old man had a C3-4 fracture-dislocation with spinal cord compression that resulted from a traffic accident. After surgery, his initial quadriparesis gradually improved. However, he complained of sudden headache and dizziness on the 5th postoperative day. His motor weakness was abruptly aggravated. Radiologic evaluation revealed an infarction in the occipital lobe and cerebellum. Cerebral angiography revealed complete bilateral VA occlusion. We administered anticoagulation therapy. After 6 months, his weakness had only partially improved. This case demonstrates that delayed infarction due to bilateral VA occlusion can occur at latencies as long as 5 days. Thus, we recommend that patients with cervical traumas that may be accompanied by bilateral VA occlusion should be closely observed for longer than 5 days.