• Journal of the Korean Society of Marine Environment & Safety
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• v.6 no.1
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• pp.47-55
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• 2000

A three-dimensional digital image processing technique is proposed to quantitatively predict the dispersion phenomena of oil droplet onto the surface of the water. This technique is able to get the dispersion rate of an oil droplet three-dimensionally just below the surface of the water over time. The obtained dispersion rate obtained through this technique is informative to the investigation into the relationship among the gravity, surface tensions between oil, water, and air. This technique is based upon the three-dimensional PIV(Particle Imaging Velocimetry) technique and its system mainly consists of a three CCD(Charge Coupled Device) cameras, an image grabber, and a host computer in which an image processing algorithm is adopted for the acquisition of dispersion rate oil an oil droplet.

• Journal of Korean Neurosurgical Society
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• v.41 no.3
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• pp.182-185
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• 2007

Acute stroke with isolated monoparesis manifesting as distal weakness of a single lower extremity has rarely been described. We report two patients with small cortical infarction who had distal weakness of a single lower extremity. In both cases, diffusion-weighted image [DWI] was used to detect small lesions in the contralateral cortex. These cases illustrate that small cortical infarction can cause isolated monoparesis limited to distal part of the leg and it may be misdiagnosed as spinal lesions, especially when lower back pain and transient sensory symptoms are accompanied. In case of the abrupt onset of weakness limited to one lower limb, the possibility of stroke should be considered and careful attention to identify cortical lesions using magnetic resonance imaging, especially DWI is required.

• The Korean Journal of Pain
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• v.31 no.1
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• pp.50-53
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• 2018

We present a patient with metastatic colon carcinoma who developed paraplegia following a neurolytic splanchnic block. A 41-year old man with metastatic adenocarcinoma of the colon received a splanchnic neurolytic block using alcohol because of severe abdominal pain. Bilateral motor weakness and a sensorial deficit in both legs developed after the procedure. Diffusion magnetic resonance imaging revealed spinal cord ischemia between T8 and L1. The motor and sensorial deficits were almost completely resolved at the end of the third month. We think that anterior spinal artery syndrome due to reversible spasms of the lumbar radicular arteries using alcohol have resulted in transient paraplegia. The retrograde spread of alcohol to neural structures may have also contributed.

• Journal of Korea Multimedia Society
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• v.23 no.1
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• pp.58-66
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• 2020

5G-based HMD technology grew rapidly in the context of the environment change of convergence technology media and mobile networks in the fourth industrial era. It has also grown into a core technology that transforms our digital visual system. However, there is no research or system that can understand and verify radical visual system changes. Therefore, it is necessary to have an engineering understanding and verification of the diffusion of HMD media imaging devices. Beyond the distinction between virtual and real, research is urgently needed on the new three-dimensional interface of the 21st century through viewer participation. For this reason, research on the algorithm structure of interactive video media using L-System is an essential process and will be a guide to understanding the virtual reality interactive environment.

• Journal of Korean Neurosurgical Society
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• v.44 no.6
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• pp.401-404
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• 2008

Primary intracranial squamous cell carcinoma is extremely rare, with most cases arising from a preexisting benign epidermoid cyst. We report a rare case of primary intracranial squamous cell carcinoma in the brain stem with a cerebellopontine angle (CPA) epidermoid cyst. A 72-year-old female suffered from progressive left hemiparesis, difficulty in swallowing, and right hemifacial numbness. Diffusion-weighted magnetic resonance imaging revealed a high signal intensity (SI) lesion in the CPA region and an intra-axially ring-enhanced cystic mass in the right brain stem with low SI. Whole-body positron emission tomography showed no evidence of metastatic disease. The histological findings revealed a typical epidermoid cyst in the CPA region and a squamous cell carcinoma in the brain stem. We speculate that the squamous cell carcinoma may have been developed due to a chronic inflammatory response by the adjacent epidermoid cyst. The patient underwent a surgical resection and radiotherapy. After 12 months, she had no evidence of recurrence.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.151-151
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• 2006

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.166-166
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• 2001

목적： 척수의 질환에 대한 확산강조영상 소견에 대하여 알아본다. 대상 및 방법： 임상적으로 진단된 척수질환 환자 8명을 (acute transverse myelitis (n=3), spinal dural AV fistula (n=2), multiple sclerosis (n=1), spinal cord tumor (n=2)) 대상으로 하였다. 영상은 Philips Intera 1.5 T system을 이용하였고, multishot spin echo EPI 펄스열 및 EKG gating을 이용하여 영상을 얻었다. 3R-R 간격으로 영상을 얻었으며 TE=72msec, FOV=25cm, 256 matrix, 5mm thickness, b value=400으로 영상매개변수를 정하였다. 척수 중심으로 3개의 절편을 얻었으며 T2 강조 영상과 겉보기확산계수 영상을 같이 구하였다.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.170-170
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• 2001

Purpose： To evaluate the relationship between reperfusion hyperemia in reversible cerebral ischem and the degree of programmed cell death. Method： We produced the animal models of reversible cerebral ischemia in 10 cats by mean of middle cerebral artery (MCA) occlusion with transorbital approach. MCA was occluded b microvascular clamp for an hour. MR imaging was performed at 0, 1, 2 days after ischemi and reperfusion. Perfusion (PWI) [Contrast enhanced GRE EPI, TR/TE= 1500/40, 40 Phases, 128 matrix, 12 cm FOV] and diffusion (DWI) (SE EPI, b=0, 500, 1000) weighted images were obtained using Philips Intera 1.57 system. rCBV and ADC maps were calculated wi IDL based postprocessing program. Tissue slices were obtained after the last MR imagin TUNEL, Calbin and Acid-Fuscin staining were done for corresponding slices as MR imagin We investigated the differences of degree of apoptosis in the area of reperfusion hyperemia.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.24-24
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• 2003

Purpose： It is known that diffusion-weighted MR imaging (DWI) is helpful in the evaluation of malignancy grading in brain tumor. This study was to evaluate the DWls with different b-values of various brain tumors in order to determine optimal b-values on 3T MR unit. Method： On a 3T MR unit, DWls with b-values of 1, 000, 3, 000 and 5, 000 s/mm2 were obtained in 20 patients of pathologically-proven brain tumors (7 metastases, 4 high grade gliomas, 2 Iymphomas, 2 low grade gliomas, 2 germinomas, and one each of germinoma, meningioma, hemangioblastoma and central neurocytoma. The overall image quality, contrast between normal brain parenchyma and tumor and signal intensities of solid and cystic components were comparatively evaluated among DWls with different b-values by visual inspection.

• The Journal of the Korean dental association
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• v.55 no.11
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• pp.800-807
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• 2017

Ultrasonography is one of the most common diagnostic tools in medical imaging with non-invasive and non-radiation loaded characteristics. In the field of dentistry, especially for periodontology, high frequency ultrasonic device can be used for several purposes such as evaluating gingival thickness, identifying the level of alveolar bone, measuring the volume of mucosa of donor site for soft tissue graft and so on. According to recent studies, it was demonstrated that ultrasonic diagnosis had both accuracy and repeatability comparable to conventional diagnostic tools. However, improvement and development of intra-oral probe suitable for adpatation to gingiva and palatal mucosa, are considered as prerequisites for diffusion of ultrasonic diagnosis in periodontology.