• Korean Journal of Optics and Photonics
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• v.25 no.2
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• pp.67-71
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• 2014

Intravascular optical coherence tomography (OCT) enables imaging of the three-dimensional (3D) microstructure of a blood vessel wall. While 3D vascular visualization provides detailed information of the vessel wall and intraluminal structures, a longitudinal imaging pitch that is several times bigger than the imaging resolution of the system has limited true high-resolution 3D imaging. In this paper we demonstrate high-speed intravascular OCT in vivo, acquiring images at a rate of 350 frames per second. A 47-mm-long rabbit aorta was imaged in 3.7 seconds, after a short flush with contrast agent. The longitudinal imaging pitch was 34 micrometers, comparable to the transverse imaging resolution of the system. Three-dimensional volume rendering showed greatly enhanced visualization of tissue microstructure and stent struts, relative to what is provided by conventional intravascular imaging speeds.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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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.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.215-222
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• 2018

This paper reports the development and performance evaluation of a backend system for real-time IVUS (Intravascular Ultrasound) imaging. The developed backend system was designed to minimize the amount of logic and memory usage by means of efficient LUTs (Look-up Tables), and it was implemented in a single FPGA (Field Programmable Gate Array) without using external memory. This makes it possible to implement the backend system that is less expensive, smaller, and lighter. The accuracy of the backend system implemented was evaluated by comparing the output of the FPGA with the result computed using a MATLAB program implemented in the same way as the VHDL (VHSIC Hardware Description Language) code. Based on the result of ex-vivo experiment using rabbit artery, the developed backend system was found to be suitable for real-time intravascular ultrasound imaging.

• Journal of Yeungnam Medical Science
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• v.36 no.2
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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.

• Biomedical Science Letters
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• v.11 no.1
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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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• v.39 no.1
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• pp.198-199
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• 2024

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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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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• v.23 no.1
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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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• v.53 no.3
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• pp.189-190
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• 2023

• The Journal of the Acoustical Society of Korea
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• v.33 no.5
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• pp.300-308
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• 2014

Photoacoustic imaging is a useful tool for the diagnosis of atherosclerosis because it is capable of providing anatomical and pathological information at the same time. A photoacoustic signal detector is a pivotal element to achieve high spatial resolution, so that it should have broadband spectrum with a high center frequency. Since a photoacoustic imaging probe is directly inserted into blood vessel to diagnose atherosclerosis, the total size of the photoacoustic signal detector should be less than 1 mm. The main purpose of this paper is to demonstrate that PVDF can be used as an active material for the photoacoustic signal detector with a high frequency and broadband characteristic. The photoacoustic signal detector developed in this study was a single element ultrasound transducer with an aperture of $0.5{\times}0.5mm$ and the total size of 1 mm. In the design stage, the natural focal depth was adjusted for an effective focal area to cover the region of interest, i.e., 1~5 mm in depth. This was because geometrical focusing could not be used due to the small aperture. Through a pulse-echo test, it was ascertained that the developed photoacoustic signal detector has the -6 dB bandwidth ranging between 40.1 and 112.8 MHz and the center frequency of 76.83 MHz.