• 산업기술연구
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• 제25권A호
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• pp.87-93
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• 2005

Three-dimensional ultrasonic probes being applied to the medical imaging can be grouped into three depending on the scanning methods, which are a mechanical type system, a free-hand system, and 2D phased arrays system. A mechanical type scanner uses a mechanically driven transducer to acquire series of 2D plane images. By integrating these images, a 3-D medical image can be constructed. A motor driving mechanism is a conventional choice for mechanically driving a transducer assembly which picks the raw ultrasonic images up. In this paper we attempt to design a 3D ultrasonic probe which has a operating mechanism of s tilting 3-D scanning. The motion of a transducer assembly of the ultrasonic probe is analytically modelled. We propose a selection procedure for the diameter of a wire rope driving the transducer assembly and the size of torsional spring which gives an initial tension to wire ropes.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
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• pp.114-114
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• 2002

Purpose： To know the fate of Gadophrin-2-enhanced areas in hearts with acute reperfused myocardial infarction. Method： The left anterior descending branches of coronary arteries were occluded for 90 min and reperfused for 60 min in 15 rabbits. Then, Gadophrin-2 (0.05 mmol/kg) was injected via ear veins. Short-axial T1-weighted spin echo images and fast cine images were obtained 24 hours after injection of Gadophrin-2. After four weeks, short-axial cine MRI was performed and T1-weighted spin echo Images were obtained 5 min and 15 min after injection of Gd-DTPA (0.2 mmol/kg). The animals were sacrificed and short-axial slices of the specimen were stained with 1.5% triphenyltetrazolium chloride (TTC) solution.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.103-107
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• 1996

In this paper, We propose an algorithm for reconstitution of chromosome images to extract its morphological feature parameters. It is reconstituted from 460 chromosome images using the 32 direction line algorithm. We extract three morphological feature parameters such as centromeric index, relative length ratio, and relative area ratio. The experiment results show that our method is batter than that of other researchers comparing with the error of feature parameters.

• Journal of Information Processing Systems
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• 제17권6호
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• pp.1170-1178
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• 2021

This paper proposed a versatile algorithm based on a dual-tree complex wavelet transform for intensifying the visual aspect of medical images. First, the decomposition of the input image into a high sub-band and low-sub-band image is done. Further, to improve the resolution of the resulting image, the high sub-band image is interpolated using Lanczos interpolation. Also, contrast enhancement is performed by singular value decomposition (SVD). Finally, the image reconstruction is achieved by using an inverse wavelet transform. Then, the Gaussian filter will improve the visual quality of the image. We have collected images from the hospital and the internet for quantitative and qualitative analysis. These images act as a reference image for comparing the effectiveness of the proposed algorithm with the existing state-of-the-art. We have divided the proposed algorithm into several stages: preprocessing, contrast enhancement, resolution enhancement, and visual quality enhancement. Both analyses show the proposed algorithm's effectiveness compared to existing methods.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 1992년도 제31차 춘계학술대회
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• pp.199.2-200
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• 1992

• Journal of Korean Neurosurgical Society
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• 제52권2호
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• pp.103-106
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• 2012

Objective : To prospectively assess the diagnostic and clinical value of a new technique (3-tesla magnetic resonance myelography, 3T MRM) as compared to computed tomographic discography (disco-CT) in patients with far lateral disc herniation. Methods : We evaluated 3T MRM and disco-CT of 25 patients, whom we suspected of suffering from far lateral disc herniation. Using an assessment scale, 4 observers examined independently both 3T MRM and disco-CT images. We analyzed observer agreement and the accentuation of each image. Results : We found complete matching, and observer agreement, between high resolution images of 3T MRM and disco-CT for diagnosing far lateral disc herniation. Conclusion : We think noninvasive 3T MRM is an appropriate diagnostic tool for far lateral disc herniation as compared to disco-CT.

• 사상체질의학회지
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• 제21권3호
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• pp.39-47
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• 2009

1. Objectives: In order to classify an individual into four constitution type, an oriental medical doctor utilizes various information such as face, pulse, voice, and questionnaire. When only one type of information is used, one's constitution may not be decided correctly. 2. Methods: In this paper, we propose a novel four constitution types classifier using facial images which classifies subjects into indecision group as well as Taeumin, Soeumin, and Soyangin. 3. Results: Experimental results show that it increases the classification rate though the decision rate is rather decreased, which is more effective and reliable than conventional classifiers without indecision. 4. Conclusion: For the effective classification, we have found that it is more useful to add an indecision group which requires more information to be properly classified into one constitution type.

• Investigative Magnetic Resonance Imaging
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• 제20권4호
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• pp.259-263
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• 2016

Primary diffuse large B-cell lymphoma of the seminal vesicle is an extremely rare disorder, with only two cases reported in the English literature. Here, we present imaging findings of a case of primary diffuse large B-cell lymphoma of the seminal vesicle. On transrectal ultrasonography, the mass presented as a 3.0-cm-sized heterogeneous, hypoechoic lesion in the right seminal vesicle. Computed tomography (CT) revealed a mass with rim-like enhancement in the right seminal vesicle. On magnetic resonance imaging (MRI), the tumor showed iso-signal intensity on T1-weighted images and heterogeneously intermediate-high signal intensity on T2-weighted images. The tumor showed rim-like and progressive enhancement with non-enhancing portion on dynamic scanning. Diffusion restriction was observed in the mass. On fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) imaging, a high standardized uptake value (maxSUV, 23.5) by the tumor was noted exclusively in the right seminal vesicle.

• 한국의학물리학회지:의학물리
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• 제16권4호
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• pp.161-165
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• 2005

CT 기종에 따라서 전자밀도에 대응하는 CT 수의 변화와 치료계획 시 선량계산에 미치는 영향을 분석하였다. 5종의 CT를 이용하여 전자밀도 교정 팬톰의 영상을 얻어 기종에 따른 CT 수의 변화를 알아보았다. 조직등가물질의 밀도에서 CT 수는 ${\pm}2\%$ 내의 차이를 보였으나 밀도가 큰 영역에서는 최대 $9.5\%$의 차이를 나타냈다. CT 수의 변화가 치료계획의 선량계산에 미치는 영향을 알아보기 위하여 환자의 흉부 영상을 이용하여 장기별로 선량의 차이를 분석한 결과 최대 $0.48\%$로 거의 차이를 보이지 않았다. 밀도가 큰 물질이 인체 내에 삽입되어 있을 경우를 가정하여 물팬톰에 CT 수가 2,000인 고밀도 물질을 삽입한 팬톰 영상을 치료계획장치에 그려 넣었다. 고밀도 물질 아래 20 cm 깊이에서 선량 계산을 비교한 결과 $2.1\%$의 차이를 보였다. 치료계획 단계에서 선량 불확도를 최소화하기 위해서는 사용되는 CT 기종에 따른 CT수와 전자밀도의 정확한 환산이 필요하며, 특히 한 기관에서 여러 종류의 CT를 이용하는 경우 각 CT 별로 전자밀도에 대응하는 CT 수를 입력하고 서로 구별하여 사용하여야한다. 또한 CT수의 재현성을 확인하기 위해 주기적인 점검이 요구된다.

• Radiation Oncology Journal
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• 제28권3호
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• pp.155-165
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• 2010

목 적: 4-dimensional computed tomography (4DCT) 영상과 on board imaging (OBI) 및 real time position management (RPM) 장치로 매 회 치료 시마다 얻은 호흡연동 직각 kilovolt (KV) 준비 영상(gated orthogonal kilovolt setup image)을 이용해 간암 환자를 치료하는 동안 발생하는 종양 위치의 불확실성을 평가하고자 했다. 대상 및 방법: 3차원입체조형치료가 예정된 20명의 간암 환자를 대상으로 RPM과 전산화단층촬영모의치료기를 이용해 치료계획용 4DCT를 시행했다. 표적 근처에 위치한 간동맥화학색전술 후 집적된 리피오돌(lipiodol) 혹은 횡격막을 종양의 위치 변이를 측정하는 표지자로 선택했다. 표지자의 위치 차이를 이용해 온라인 분할간 및 분할중 내부 장기 변이와 움직임 진폭을 측정했다. 측정된 자료의 정량적 평가를 위해 통계 분석을 실시했다. 결 과: 20명 환자로부터 측정된 표지자의 분할간변이의 중앙값은 X (transaxial), Y (superior-inferior), Z (anterior-posterior) 축에서 각각 0.00 cm (범위, -0.50~0.90 cm), 0.00 cm (범위, -2.4~1.60 cm), 0.00 cm (범위, -1.10~0.50 cm) 였다. 4명의 환자에서 X, Y, Z축 중 하나 이상에서 0.5 cm를 초과하는 변이가 관찰되었다. 4DCT와 호흡연동 직각 준비 영상으로부터 얻은 표적의 움직임 진폭의 차이는 X, Y, Z 축에서 각각 중앙값이 -0.05 cm (범위, -0.83~0.60 cm), -0.15 cm (범위, -2.58~1.18 cm), -0.02 cm (범위, -1.37~0.59 cm) 였다. 두 영상간 표적의 움직임 진폭 차이가 1 cm를 초과하는 환자가 Y축 방향으로 3명 관찰되었으며, 0.5 cm 초과 1 cm 미만의 차이를 보이는 환자도 Y축과 Z축 방향을 합쳐 5명 관찰되었다. 분할중 표지자 위치 변이의 중앙값은 X, Y, Z축에서 각각 0.00 cm (범위, -0.30~0.40 cm), -0.03 cm (범위, -1.14~0.50 cm), 0.05 cm (범위, -0.30~0.50 cm)였으며 2명의 환자에서 1 cm를 초과하는 변이가 Y축 방향으로 관찰되었다. 결 론: 4DCT와 호흡연동 직각 KV 준비 영상으로 얻은 표지자의 분할간, 분할중 및 움직임 진폭에서 큰 변이가 관찰되었다.