• 한국광학회지
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• 제25권2호
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• pp.67-71
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• 2014

혈관 내 OCT (optical coherence tomography) 는 혈관 벽 내부의 3차원적 미세구조를 영상화할 수 있어서 임상에서 각광을 받고 있다. 하지만 아직도 충분하지 못한 이미징 속도, 특히 내시경 프로브의 이미징 광 스캐닝 속도의 부족으로 혈관 길이 방향의 이미징 간격이 실제 시스템의 광학적 해상도보다 5배 이상 커서 혈관 종방향으로의 고해상도 이미징이 얻어지지 못하고 있는 상황이다. 본 논문에서는 초당 350장의 혈관 벽 단층 영상을 제공하는 고속 혈관 내 OCT 시스템을 기술한다. 본 시스템과 내시경 장치를 이용하여 47 mm 길이의 살아있는 토끼 대동맥을 3.7초만에 34 micron의 혈관 종방향 간격으로 얻는데 성공하였다. 34 micron의 종방향 간격은 실제 내시경의 그 방향 광학적 해상도와 비슷한 정도로서 3차원 모든 방향으로의 고해상도 이미징을 구현하였음을 보여준다. 얻어진 이미징 데이터의 3차원 영상 구현을 통해 혈관의 미세구조 및 이미징 전 삽입된 스텐트의 자세한 구조를 보였다.

• Nuclear Medicine and Molecular Imaging
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• 제43권4호
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• pp.352-356
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• 2009

Intravascular large B-cell lymphoma (IVLBCL) is a subtype of diffuse large cell lymphoma, characterized by proliferation of lymphoid cells in the intravascular space of various organs without causing a mass effect. Although $^{18}$F-FDG PET is a powerful imaging tool in lymphoma, the usefulness of $^{18}$F-FDG PET in the assessment of IVLBCL is still controversial. $^{99m}$Tc-MIBI, a tumor imaging radiopharmaceutical with a different mechanism from that of $^{18}$F-FDG, has been reported to be also effective in lymphoma. However, there is nearly no report on the efficacy of $^{99m}$Tc-MIBI in the assessment of IVLBCL. We present one case of IVLBCL that showed $^{99m}$Tc-MIBI accumulation in the involved bone marrow as an incidental finding, which was discrepant from that of $^{18}$F-FDG PET.

• 한국음향학회지
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• 제37권4호
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• pp.215-222
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• 2018

본 논문은 실시간 혈관내초음파 영상을 위한 후단부 시스템 개발과 성능 평가 결과에 관한 것이다. 개발한 후단부 시스템은 로직 사용량과 메모리 사용량을 최소화할 수 있는 효율적인 LUTs (Look-up Tables)을 사용하여 외부 메모리 없이 하나의 FPGA (Field Programmable Gate Array)만으로 시스템을 구성함으로써 시스템의 저비용, 소형화, 경량화가 가능하도록 설계하였다. 구현한 후단부 시스템의 정확도는 FPGA의 출력값과 VHDL (VHSIC Hardware Description Language) 코드를 MATLAB 프로그램을 사용하여 동일하게 구현하여 얻은 결과를 비교함으로써 검증하였다. 토끼 동맥을 이용한 ex-vivo 실험을 통하여 개발한 후단부 시스템이 실시간 혈관내초음파 영상에 적합함을 확인하였다.

• Journal of Yeungnam Medical Science
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• 제36권2호
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• pp.109-114
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• 2019

Background: Transforaminal epidural block (TFEB) is an effective treatment option for radicular pain. To reduce complications from intravascular injection during TFEB, use of imaging modalities such as real-time fluoroscopy (RTF) or digital subtraction angiography (DSA) has been recommended. In this study, we investigated whether DSA improved the detection of intravascular injection during TFEB at the whole spine level compared to RTF. Methods: We prospectively examined 316 patients who underwent TFEB. After confirmation of final needle position using biplanar fluoroscopy, 2 mL of nonionic contrast medium was injected at a rate of 0.5 mL/s under RTF; 30 s later, 2 mL of nonionic contrast medium was injected at a rate of 0.5 mL/s under DSA. Results: Thirty-six intravascular injections were detected for an overall rate of 11.4% using RTF, with 45 detected for a rate of 14.2% using DSA. The detection rate using DSA was statistically different from that using RTF (p=0.004). DSA detected a significantly higher proportion of intravascular injections at the cervical level than at the thoracic (p=0.009) and lumbar (p=0.011) levels. Conclusion: During TFEB at the whole spine level, DSA was better than RTF for the detection of intravascular injection. Special attention is advised for cervical TFEB, because of a significantly higher intravascular injection rate at this level than at other levels.

• 대한의생명과학회지
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• 제11권1호
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• pp.23-29
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• 2005

Molecular imaging with targeted contrast agents enables tissues to be distinguished by detecting specific cell-surface receptors. In the present study, a ligand-targeted acoustic nanoparticle system is used to identify angioplasty-induced expression of tissue factor by smooth muscle cell within carotid arteries. Pig carotid arteries were overstretched with balloon catheters, treated with tissue factor-targeted or a control nanoparticle system, and imaged with intravascular ultrasound before and after treatment. Tissue factor-targeted emulsion bound and increased the echogenicity and gray-scale levels of overstretched smooth muscle cell within the tunica media, versus no change in contralateral control arteries. Expression of stretch-induced tissue factor in carotid artery media was confirmed by immunohistochemistry. The potential for abnormal thrombogenicity of balloon-injured arteries, as reflected by smooth muscle expression of tissue factor, was imaged using a novel, targeted, nanoparticulate ultrasonic contrast agent.

• The Korean journal of internal medicine
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• 제39권1호
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• pp.198-199
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• 2024

• Journal of Korean Neurosurgical Society
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• 제52권1호
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• pp.52-54
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• 2012

A 10-year-old female patient presented with a rapidly growing nodular mass lesion on her right frontal area. On skull radiography and computed tomography (CT) imaging, this mass had a well-demarcated punch-out lesion with a transdiploic, exophytic soft tissue mass nodule on the frontal scalp. Magnetic resonance (MR) imaging revealed the presence of a $1.5{\times}1.2{\times}1$ cm sized calvarial lesion. This lesion was hypointense on T1 and heterogenous hyperintense on T2 weighted MR images, and exhibited heterogeneous enhancement of the soft tissue filling the punch-out lesion after intravenous administration of gadolinium. En block removal of the tumor with resection of the rim of the normal bone was performed. The pathological diagnosis was intravascular papillary endothelial hyperplasia (IPEH). After surgery, no recurrence was found for 8 months. IPEH is a rare and benign reactive lesion usually found in thrombosed subcutaneous blood vessels. Involvement of skull bone is rare. In this article, we present a case of IPEH involving the calvarium, in a 10-year-old woman.

• The Korean Journal of Pain
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• 제23권1호
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• pp.18-23
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• 2010

Background: Complications following lumbar transforaminal epidural injection are frequently related to inadvertent vascular injection of corticosteroids. Several methods have been proposed to reduce the risk of vascular injection. The generally accepted technique during epidural steroid injection is intermittent fluoroscopy. In fact, this technique may miss vascular uptake due to rapid washout. Because of the fleeting appearance of vascular contrast patterns, live fluoroscopy is recommended during contrast injection. However, when vascular contrast patterns are overlapped by expected epidural patterns, it is hard to distinguish them even on live fluoroscopy. Methods: During 87 lumbar transforaminal epidural injections, dynamic contrast flows were observed under live fluoroscopy with using digital subtraction enhancement. Two dynamic fluoroscopy fluoroscopic images were saved from each injection. These injections were performed by five physicians with experience independently. Accuracy of live fluoroscopy was determined by comparing the interpretation of the digital subtraction fluoroscopic images. Results: Using digital subtraction guidance with contrast confirmation, the twenty cases of intravascular injection were found (the rate of incidence was 23%). There was no significant difference in incidence of intravascular injections based either on gender or diagnosis. Only five cases of intravascular injections were predicted with either flash or aspiration of blood (sensitivity = 25%). Under live fluoroscopic guidance with contrast confirmation to predict intravascular injection, twelve cases were predicted (sensitivity = 60%). Conclusions: This finding demonstrate that digital subtraction fluoroscopic imaging is superior to blood aspiration or live fluoroscopy in detecting intravascular injections with lumbar transforaminal epidural injection.

• Korean Circulation Journal
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• 제53권3호
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• pp.189-190
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• 2023

• 한국음향학회지
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• 제33권5호
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• pp.300-308
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• 2014

광음향 영상은 조직의 형태학적 정보뿐만 아니라 병리학적 정보도 함께 제공할 수 있어 죽상동맥경화증 진단에 유용하게 사용될 수 있다. 높은 해상도의 광음향 영상을 획득하기 위해서는 광음향 신호를 수신할 초음파 변환기가 고주파수 및 광대역 특성을 가져야만 한다. 또한 죽상동맥경화증 진단을 위해서는 혈관에 변환기를 직접 삽입하여 광음향 영상 신호를 획득해야하기 때문에 그 크기가 1 mm 이하가 되어야만 한다. 본 논문에서는 PVDF 압전 소재를 이용하여 혈관내 광음향 영상을 위한 고주파수, 광대역 특성을 갖는 초음파 변환기 제작이 가능함을 보였다. 개발한 광음향 수신 변환기는 단일소자이며 구경은 $0.5{\times}0.5mm$이고 전체 변환기 크기는 직경이 1 mm이내가 되도록 하였다. 작은 크기로 인해 형태학적 빔집속이 아닌 자연집속 깊이를 조절하여 관심영역(1~5 mm)에서 빔집속이 되도록 설계하였다. 제작한 혈관내 광음향 수신 변환기의 주파수 특성을 펄스-에코 응답실험을 통해 알아보았다. 제작된 변환기는 -6 dB 대역폭이 40.1~112.8 MHz이며, 중심 주파수가 76.83 MHz인 고주파수 및 광대역 특성을 갖는다는 것을 실험적으로 확인하였다.