• Journal of Korean Neurosurgical Society
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• 제58권3호
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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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• 제46권6호
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• pp.577-580
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• 2009

A 47-year-old man presented with a subarachnoid hemorrhage (SAH) and right cerebellar hematoma was referred for evaluation. Cerebral angiography revealed a distal anterior inferior cerebellar artery (AICA) aneurysm associated with an arteriovenous malformation (AVM). Successful obliteration and complete removal of the aneurysm and AVM were obtained using transcortical approach under the guidance of neuronavigation system. The association of a peripheral AICA aneurysm and a cerebellar AVM by the same artery is unique. The reported cases of conventional surgery for this disease complex are not common and their results are variable. Less invasive surgery using image-guided neuronavigation system would be helpful and feasible for a peripheral aneurysm combining an AVM of the posterior fossa in selective cases

• Journal of Korean Neurosurgical Society
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• 제44권3호
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• pp.159-162
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• 2008

Stenting is a useful alternative treatment modality in carotid artery stenosis patients who are too high-risk to undergo carotid endarterectomy (CEA). We report a case of contralateral cerebral infarction after stenting for extracranial carotid stenosis. A 78-year-old woman was admitted to the hospital with left-sided weakness. Based on magnetic resonance imaging (MRI) of the brain and conventional angiography, she was diagnosed with an acute watershed infarct of the right hemisphere secondary to severe carotid stenosis. Stenting was performed for treatment of the right carotid artery stenosis after a one-week cerebral angiogram was completed. Thirty minutes after stent placement, the patient exhibited a generalized seizure. Four hours later, brain MRI revealed left hemispheric cerebral infarction. Complex aorta-like arch elongation, tortuosity, calcification, and acute angulation at the origin of the supra-aortic arteries may increase the risk of procedural complications. In our case, we suggest that difficult carotid artery catheterization, with aggressive maneuvering during stenting, likely injured the tortuous, atherosclerotic aortic arch, and led to infarction of the contralateral cerebral hemisphere by thromboemboli formed on the wall of the atherosclerotic aorta.

• Clinical and Experimental Pediatrics
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• 제54권1호
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• pp.40-44
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• 2011

We present a case of tacrolimus-induced encephalopathy after successful kidney transplantation. An 11-year-old girl presented with sudden onset of neurologic symptoms, hypertension, and psychiatric symptoms, with normal kidney function, after kidney transplantation. The symptoms improved after cessation of tacrolimus. Magnetic resonance imaging (MRI) showed acute infarction of the middle cerebral artery (MCA) territory in the right frontal lobe. Three days later, she had normal mental function and maintained normal blood pressure with left hemiparesis. Follow-up MRI was performed on D19, showing new infarct lesions at both cerebral hemispheres. Ten days later, MRI showed further improvement, but brain single photon emission computed tomography (SPECT) showed mild reduction of uptake in both the anterior cingulate gyrus and the left thalamus. One month after onset of symptoms, angiography showed complete resolution of stenosis. However, presenting as a mild fine motor disability of both hands and mild dysarthria, what had been atrophy at both centrum semiovale at 4 months now showed progression to encephalomalacia. There are two points of interest in this case. First, encephalopathy occurred after administration of tacrolimus and improved after discontinuation of the drug. Second, the development of right-side hemiplegia could not be explained by conventional MRI; but through diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) of white matter tract, visualization was possible.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.420-423
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• 2002

In recent years, there has been keen interest in developing f1at panel detectors for all modalities of radiology, including gerneral radiology, fluoroscopy(angiography and cardiology), electronic portal imaging, and mammography. In this paper, we report the new hybrid x-ray detector consisted of CsI(Tl) photoemission layer and a-Se photoconductor layer to resolve conventional x-ray detector such as the direct detector using a-Se and the indirect detector using CsI(Tl)/a-Si. To design the structure of CsI(Tl)/a-Se detector, the penetrated energy spectrum and absorption fraction was estimated using MCNP 4C code. Experimental results showed that the absorption fraction of $500{\mu}m-Se$ film and $150{\mu}m-CsI\left(Tl \right)/a-Se\left( 30{\mu}m \right)$ film is 70% at 70 kVp. The absorption energy is 90% at $350{\mu}m-CsI(Tl)$.

• Journal of International Society for Simulation Surgery
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• 제1권2호
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• pp.75-79
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• 2014

Purpose The region growing has a critical problem that it often extract vessels with unexpected objects such as a bone which has a similar intensity characteristics to the vessel. We propose the new method to extract arterial vascular anatomy around the stomach from the CTA volume without the post-processing. Materials and Methods Our method, which is also based on the region growing, requires the two seed points from the use. I automatically extracts perigastric arteries using the adaptive region growing method and it does not need any post-processing. Results The three region growing based methods are used to extract perigastric arteries - the conventional region growings with restrict and loose thresholds each and the proposed method. The 3D visualization from the result of our method shows our method extracted the all required arteries for gastric surgery. Conclusion By extracting perigastric arteries using the proposed method, over-segmentation problem that unexpected anatomical objects such as a rib or backbone are also segmented does not occurs anymore. The proposed method does not need to sensitively determine the thresholds of the similarity function. By visualizing the result, the preoperative simulation of arterial vascular anatomy around the stomach can be possible.

• Journal of Yeungnam Medical Science
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• 제23권1호
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• pp.113-117
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• 2006

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that may affect many organ systems including the nervous system. The immune response in patients with SLE can cause inflammation and other damage that can cause significant injury to the arteries and tissues. A 48-year-old woman was admitted to the hospital because of transient monocular blindness. Magnetic resonance imaging and conventional angiography showed severe stenosis of the distal intracranial internal carotid artery. The patient was diagnosed as having SLE but the antiphospholipid antibodies were negative. Amaurosis fugax has not been previously reported as an initial manifestation of SLE in Korea. We report a patient with a retinal transient ischemic attack as the first manifestation of SLE.

• Journal of Radiation Protection and Research
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• 제47권1호
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• pp.39-49
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• 2022

Background: For proper monitoring of the eye lens dose, an appropriate calibration factor of a dosimeter and information about the mean energies of X-rays are indispensable. The scattered X-ray energy spectra should be well characterized in medical practices where eye lenses of medical staffs might be high. Materials and Methods: Scattered X-ray energy spectra were experimentally derived for three different types of X-ray diagnostic and therapeutic equipment, i.e., the computed tomography (CT) scan, the angiography and the fluoroscopy. A commercially available CdZnTe (CZT) spectrometer with a lead collimator was employed for the measurement of scattered X-rays, which was performed in the usual manner. Results and Discussion: From the obtained energy spectra, the mean energies of the scattered X-rays lied between 40 and 60 keV. This also agreed with that obtained by the conventional half value layer method. Conclusion: The scattered X-rays to which medical workers may be exposed in the region around the eyes were characterized by means of spectrometry. The obtained mean energies of the scattered X-rays were found to match the flat region of the dosimeter response.

• 대한중풍순환신경학회지
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• 제10권1호
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• pp.54-61
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• 2009

Arteriosclerosis is a pathologic term that contains hardening of arterial wall, loss of arterial elasticity and stenosis of artery. To diagnose this disease, conventional angiography, MRA, transcranial doppler ultrasonography are commonly used. And it causes various clinical phases by a region of the disease. In oriental medicine, arteriosclerosis is classified into congested fluids(痰飮), blood stasis(瘀血), stagnation of Gi(氣滯) and treated by Herb-Med, acupuncture, cupping, moxibustion, and the like. The purpose of this study was to investigate the effect of oriental medical therapy on cerebral arteriosclerosis. A patient with cerebrovascular disease admitted due to dizziness, mild dysarthria, tinnitus, anxiety disorder and his Brain MRA showed severe arteriosclerosis in right anterior cerebral artery(ACA) and middle cerebral artery(MCA). Every day, we administered to patient Herb Med and Herb pills. Also, acupuncture, moxibustion were done, too. As a result of the treatment, the patient's follow up Brain MRA showed improved state of ACA stenosis.

• Investigative Magnetic Resonance Imaging
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• 제7권1호
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• pp.12-21
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• 2003

목적 : 기존의 일반적인 스펙트로미터보다 향상된 성능을 가진 새로운 스펙트로미터를 설계 및 제작하였다. 대상 및 방법 : 초당 10억번의 부동 연산 능력을 갖춘 TMS320C6701 DSP를 이용하여 연속적으로 변하는 복잡한 경사자계파형을 실시간으로 계산하여 출력할 수 있고, 선택 단면을 interactive하게 조절할 수 있는 스펙트로미터를 설계, 제작하였다. 설계된 스펙트로미터는 DSP 기반의 디지털 제어부와 파형을 만들고 변조 및 복조를 수행하는 아날로그부로 구성되어 있다 RF 신호의 변조 및 복조는 디지털 기술을 사용하여 정밀도와 안정성을 높였다. 고속 병렬영상을 위하여 하나의 측정 보드당 4채널까지 측정할 수 있도록 하였고, 고속 DSP를 이용하여 빠른 재구성이 가능하도록 하였다. 결과 : 제작된 스펙트로미터를 1.5 테슬라 전신자기공명영상 시스템에 장착하여 다양한 방법으로 성능을 시험하였다. 디지털 변조/복조 방식에서 요하는 정밀한 위상 제어를 확인할 수 있었고, phase array 코일 영상을 통하여 다중 채널 측정시스템의 성능을 검증할 수 있었다. 개발된 스펙트로미터를 기존의 상품화된 스펙트로미터와 비교해 볼때 보다 정밀한 위상 제어가 가능한 것으로 나타났다. 결론 : Interactive하게 영상의 단면을 선택하고, 실시간 계산에 의한 파형출력은 나선주사 심장영상과 같은 첨단의 영상기법에 요구되는 스펙트로미터의 기능이다 또한 다채널 측정시스템도 병렬영상을 위한 필수적인 기능이다. 본 논문에서는 초당 10억번의 부동소수점 연산이 가능한 TMS320C6701 디지털신호처리기를 사용하여 이러한 기능들을 가진 스펙트로미터를 설계, 제작하였다. 디지털 방식의 변조/복조 기술을 채택하여 정밀한 위상제어가 가능하였다. 개발된 스펙트로미터를 FSE, GE, angiography 등 다양한 영상방법에 적용하여 성능을 확인하였으며, 기존의 제품보다 뛰어난 화질의 영상을 얻을 수 있었다.