• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.184-191
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• 2007

Our objective was to develop and evaluate a non-invasive device for rigid immobilization and surface disease non-contact of the table in the lower extremity during CT angiography. The immobilization device consists of two components. The patient's lower limb device stabilizing elements made of polyethylene resin soft materials, and pelvis parts foam pad is used for non-contact surface. In a Prospective study the lower extremity device was used in patients who underwent a CT angiography of the lower limb. Immobilization with our device was well tolerated by all patients. The quality of the resulting images in the popliteal and infrapopliteal region was rated by five-point scale. The rigid immobilization resulted in a complete absence of motion artifacts. The new device is an effective, well tolerated and easily used immobilization that is suitable of use in 3D lower extremity CT angiography.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2697-2700
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• 2003

이 논문에서는 3 차원 CT/CTA 영상 데이터에 대하여 고속 자동 정합 기법을 제안한다. 제안하는 기법은 다해상도 (multi-resolution) 구조의 정규 상호 정보량(normalized mutual information) 을 최대화하는 정합 방식에서, 정합 유사도를 계산하는 볼륨 영역을 효율적으로 줄여 정합 속도를 증가시키는 방법이다. 제안된 정합방식을 CT/CTA (CT angiography) 팬텀 데이터와 7 세트의 실제 CT/CTA 임상 데이터에 적용하여 테스트하였다. 이로부터 제안하는 방식이, 정합 정확도를 유지하는 동시에 정합 속도를 10 ∼ 60％ 로 감소시킴을 확인 할 수 있었다. 또한 제안된 정합 방식을 DS-CTA (digital subtraction CT angiography) 에 적용하여, CT/CTA 영상으로부터 혈관 영상을 성공적으로 추출하였다.

• Journal of Magnetics
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• v.20 no.1
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• pp.40-46
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• 2015

This study investigated the accuracy of magnetic resonance angiography (MRA) and computed tomography angiography (CTA) in terms of reflecting the actual vascular length. Three-dimensional time of flight (3D TOF) MRA, 3D contrast-enhanced (CE) MRA, volume-rendering after CTA and maximum intensity projection were investigated using a flow model phantom with a diameter of 2.11 mm and area of $0.26cm^2$. 1.5 and 3.0 Tesla devices were used for 3D TOF MRA and 3D CE MRA. CTA was investigated using 16 and 64 channel CT scanners, and the images were transmitted and reconstructed by volume-rendering and maximum intensity projection, followed by conduit length measurement as described above. The smallest 3D TOF MRA measure was $2.51{\pm}0.12mm$ with a flow velocity of 40 cm/s using the 3.0 Tesla apparatus, and $2.57{\pm}0.07mm$ with a velocity of 71.5 cm/s using the 1.5 Tesla apparatus; both images were magnified from the actual measurement of 2.11 mm. The measurement with the 16 channel CT scanner was smaller ($3.83{\pm}0.37mm$) than the reconstructed image on maximum intensity projection. The images from CTA from examination apparatus and reconstruction technique were all larger than the actual measurement.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.61-68
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• 2020

The purpose of this study is to investigate the correlation of blooming artifacts according to dilution ratio of contrast agent on CT angiography images. A total of 10 sets were prepared by differently setting the ratio of contrast media and saline in a ball phantom made by a 3D printer. CT scan images were obtained and reconstructed by MIP and MPR techniques to obtain axial, sagittal and coronal images, respectively. After, the diameter of the ball phantom of the image obtained after the test was measured each 30 times, a total 1800 times. As a result, the dilution of 20:80 in the coronal plane was the smallest (p<0.05). Similarly, when dilute to 20:80 in the sagittal plane of MIP, it was the smallest as 20.39 ± 0.08 mm (p<0.05). Correlation analysis between dilution ratio and measurement size confirmed strong negative correlations in all reconstructed images (p<0.05). In conclusion, the higher the dilution ratio of the contrast agent, the more difficult it is to measure actual blood vessel measurement. Therefore, this study may provide basic data in future studies on actual measurement.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.961-968
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• 2019

The purpose of this study was to evaluate the usefulness of cerebral angiography in each energy level by using dual energy technique in CT. Methods were performed on 15 DE images and SE images of CT angiography. For the analysis of images, mean value, standard deviation, SNR and CNR value were determined by setting ROI on MCA, brain parenchyma tissue, and back ground. As a result of concurrent visual evaluation with Likert 5 point scale, the clearest MCA image was confirmed at DE 40 keV and SE 120 kVp(p>0.05). The SNR value of the SE image was measured to be similar to the 40 keV energy level of the DE image. The low energy level image of 40 keV and 50 keV was measured with a high SNR and the contrast ratio was higher than that of the high energy image.

• Journal of KIISE:Software and Applications
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• v.31 no.7
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• pp.939-948
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• 2004

In this paper. we Propose a robust and fast image registration technique for motion correction in brain CT-CT angiography obtained from same patient to be taken at different time. First, the feature points of two images are respectively extracted by 3D edge detection technique, and they are converted to locally weighted 3D distance map in reference image. Second, we search the optimal location whore the cross-correlation of two edges is maximized while floating image is transformed rigidly to reference image. This optimal location is determined when the maximum value of cross-correlation does't change any more and iterates over constant number. Finally, two images are registered at optimal location by transforming floating image. In the experiment, we evaluate an accuracy and robustness using artificial image and give a visual inspection using clinical brain CT-CT angiography dataset. Our proposed method shows that two images can be registered at optimal location without converging at local maximum location robustly and rapidly by using locally weighted 3D distance map, even though we use a few number of feature points in those images.

• Journal of Korean Neurosurgical Society
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• v.41 no.4
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• pp.230-235
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• 2007

Objective : We investigated the incidence of the vascular abnormalities associated with spontaneous intracerebral hemorrhage [ICH] using three-dimensional computed tomographic angiography [3D-CTA]. Methods : We prospectively assessed consecutive 76 patients with spontaneous intracerebral hemorrhage [ICH] who underwent 3D-CTA between June 2003 and May 2005. The patients with a recent history of trauma or mainly subarachnoid hemorrhage were excluded. We investigated relationship between vascular abnormality and ICH location. The findings of 3D-CTA were classified as one of three patterns with ICH; type A [without evidence of vascular abnormality], type B [with no vascular abnormality as the source of hemorrhage, but with incidental vascular abnormality], and type C [presence of a vascular abnormality as the source of hemorrhage]. Results : Sites of ICH were lobar 26, basal ganglia 23, thalamus 17, posterior fossa 6 and dominant intraventricular hemorrhage [IVH] 4. Among 76 patients, sixteen [21.1%] vascular abnormalities were noted excluding 13 cases of stenoocclusive disease. Sixteen cases included 6 cases of cerebral aneurysms [7.9%], 5 moyamoya diseases [6.6%], 4 arteriovenous malformations [5.3%] and 1 dural sinus thrombosis [1.3%]. Lobar ICH [30.8%] had a higher vascular abnormalities than other types, and younger age [<40] group had a higher incidence of vascular abnormalities than old age group. The patterns of 3D-CTA include sixty cases [79.0%] of type A, 6 cases [7.8%] of type Band 10 cases [13.2%] of type C. The vascular abnormalities were found in 8 [13.5%] of 59 hypertensive patients and 8 [47.0%] of 17 non-hypertensive patients [p=0.006]. Conclusion : 3D-CT angiography is considered a useful screening tool for ICH patients with suspected cerebrovascular abnormalities and should be considered in such clinical settings, especially in lobar type and in non-hypertensive younger patients.

• Journal of Korean Neurosurgical Society
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• v.50 no.1
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• pp.6-10
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• 2011

Objective : Spontaneous acute subdural hematomas (aSDH) secondary to ruptured intracranial aneurysms are rarely reported. This report reviews the clinical features, diagnostic modalities, treatments, and outcomes of this unusual and often fatal condition. Methods : We performed a database search for all cases of intracranial aneurysms treated at our hospital between 2005 and 2010. Patients with ruptured intracranial aneurysms who presented with aSDH on initial computed tomography (CT) were selected for inclusion. The clinical conditions, radiologic findings, treatments, and outcomes were assessed. Results : A total of 551 patients were treated for ruptured intracranial aneurysms during the review period. We selected 23 patients (4.2%) who presented with spontaneous aSDH on initial CT. Ruptured aneurysms were detected on initial 3D-CT angiography in all cases. All ruptured aneurysms were located in the anterior portion of the circle of Willis. The World Federation of Neurosurgical Societies grade on admission was V in 17 cases (73.9%). Immediate decompressive craniotomy was performed 22 cases (95.7%). Obliteration of the ruptured aneurysm was achieved in all cases. The Glasgow outcome scales for the cases were good recovery in 5 cases (21.7%), moderate disability to vegetative in 7 cases (30.4%), and death in 11 cases (47.8%). Conclusion : Spontaneous aSDH caused by a ruptured intracranial aneurysm is rare pattern of aneurysmal subarachnoid hemorrhage. For early detection of aneurysm, 3D-CT angiography is useful. Early decompression with obliteration of the aneurysm is recommended. Outcomes were correlated with the clinical grade and CT findings on admission.

• Korean Journal of Digital Imaging in Medicine
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• v.3 no.1
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• pp.212-216
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• 1997

• Proceedings of the Korean Society of Radiological Science
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• 1994.05a
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• pp.26.2-27
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• 1994