• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.373-378
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• 2004

하모니 영상은 초음파의 비선형 전파 과정에서 발생된 하모닉 성분을 영상화 한다. 하모닉 영상은 초음파에 비선형적으로 반응하는 초음파 조영제를 사용하여 하모닉 성분의 발생을 최대화 하고 있다. 일반적으로 현재 임상적으로 사용되는 하모닉 영상은 2차 고주파 성분을 사용한 것을 의미한다. 2차 하모닉 영상은 주파수의 상승으로 공간 분해능이 향상된다. 초음파 조영제를 이용하는 경우 서브 하모닉, 울트라 하모닉의 발생도 유의할 것으로 기대되지만 이에 대한 연구는 거의 없는 실정이다. 서브 하모닉은 상대적으로 2차 하모닉보다 전파 과정에서 감쇠 효과가 작기 때문에 심부의 영상에 유리하다 서브 하모닉 및 울트라 하모닉 성분 검출은 초음파 변환기의 대역폭에 대한 제한을 2차 하모닉에 비해 상대적으로 덜 받는다. 본 연구에서는 진단용 초음파에 의해 초음파 조영제에서 방사하는 하모닉 성분의 크기를 시뮬레이션 하였다. 수치해석은 Gilmore Equation을 이용하였으며, 초음파 조영제의 탄성 효과는 무시하였다. 초음파 조영제의 크기와 초음파의 MI에 따라 하모닉 성분의 크기를 정량적으로 비교하고, 서브 및 울트라 하모닉 영상의 구현에 대해 토의하였다.

• Ultrasonography
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• v.32 no.1
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• pp.59-65
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• 2013

Purpose: The purpose of this study is to establish the methodology regarding synthesis of ultrasound contrast agent imaging, and to evaluate the characteristics of the synthesized ultrasound contrast agents, including size or degradation interval and image quality. Materials and Methods: The ultrasound contrast agent, composed of liposome and SF6, was synthesized from the mixture solution of $21{\mu}mol$ DPPC (1, 2-Dihexadecanoyl-sn-glycero-3-phosphocholine, $C_{40}H_{80}NO_8P$), $9{\mu}mol$ cholesterol, $1.9{\mu}mol$ of DCP (Dihexadecylphosphate, $[CH_3(CH_2)_{15}O]_2P(O)OH$), and chloroform. After evaporation in a warm water bath and drying during a period of 12-24 hours, the contrast agent was synthesized by the sonication process by addition of buffer and SF6 gas. The size of the contrast agent was controlled by use of either extruder or sonication methods. After synthesis of contrast agents, analysis of the size distribution of the bubbles was performed using dynamic light scattering measurement methods. The degradation curve was also evaluated by changes in the number of contrast agents via light microscopy immediate, 12 hours, 24 hours, 36 hours, 48 hours, 60 hours, 72 hours, and 84 hours after synthesis. For evaluation of the role as an US contrast agent, the echogenicity of the synthesized microbubble was compared with commercially available microbubbles (SonoVue, Bracco, Milan, Italy) using a clinical ultrasound machine and phantom. Results: The contrast agents were synthesized successfully using an evaporation-drying-sonication method. The majority of bubbles showed a mean size of 154.2 nanometers, and they showed marked degradation 24 hours after synthesis. ANOVA test revealed a significant difference among SonoVue, synthesized contrast agent, and saline (p < 0.001). Although no significant difference was observed between SonoVue and the synthesized contrast agent, difference in echogenicity was observed between synthesized contrast agent and saline (p < 0.01). Conclusion: We could synthesize ultrasound contrast agents using an evaporation-drying-sonication method. On the basis of these results, many prospective types of research, such as anticancer drug delivery, gene delivery, including siRNA or microRNA, targeted molecular imaging, and targeted therapy can be performed.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2
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• pp.78-86
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• 2005

This study considers the magnitude of the harmonic components radiated from the ultrasonic contrast agents (UCA) activated by a typical diagnostic ultrasound. The nonlinear dynamic response of UCA to a 2 MHz diagnostic ultrasound pulse was predicted using Gilmore Model. The elastic property of the shell membrane of the UCA was ignored in the numerical model. Simulation was carried out for the UCA varying from 1 - 9 $\mu$m in its initial radius and the driving diagnostic ultrasound whose mechanical index (MI) ranges from 0.125 to 8. The powers of the sub. ultra and second harmonics of the acoustic signal from the UCA activated were compared with that of the fundamental component. The results show that. if the UCA is bigger than its resonant size (2 $\mu$m in radius for the present case) the sub harmonic power was much bigger than the fundamental. In particular, the 2nd harmonic component currently used as an imaging parameter for the harmonic imaging, was predicted to be lower in power than both the sub and the ultra harmonic component. This study indicates that, for obtaining harmonic imaging with UCA, the sub or ultra harmonics could be taken as imaging parameters better than the 2nd harmonic component.

• Journal of KSNVE
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• v.10 no.5
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• pp.743-759
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• 2000

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.5 no.1
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• pp.9-14
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• 2012

Purpose: The purpose of the study was to evaluate the accuracy and clinical outcome of ultrasound-guided glenohumeral joint steroid injection on adhesive capsulitis. Materials and Methods: Patients who were diagnosed as adhesive capsulitis by MRI and physical examination and did not improve their symptom with physical therapy and NSAIDS treatment more than 6 months were included in the study. Patients who showed any other shoulder pathology or history if trauma were excluded from the study. 33 patients including 15 males and 18 females were enrolled in the study, the average age being 55.1 (age 42~72). Cocktail of steroid, lidocaine, saline and contrast medium injected inside shoulder glenohumeral joint using novel approach (which we called acromioclavicular approach) under ultrasound guidance. Clinical outcome was measured through passive range of motion and VAS scoring system. Results: Based on radiographic findings, cases were classified according to the leakage of contrast medium; perfect confinement of contrast-medium inside the capsule, partial leakage of the medium and contrast-medium found at outside the joint. Total 25 cases (76%) out of 33 cases showed perfect confinement of contrast-medium inside the glenohumeral joint. Partial leakage was observed in 6 cases (18%), and contrast medium was observed outside of the glenohumeral joint in 2 cases (6%). Perfect-confinement group showed $111^{\circ}$($80{\sim}140^{\circ}$) of forward flexion and $48^{\circ}$($0{\sim}90^{\circ}$) of external rotation before injection, and improved to $134^{\circ}$($90{\sim}150^{\circ}$) of forward flexion and $70^{\circ}$($30{\sim}90^{\circ}$) of external rotation after injection (p<0.01). Partial leakage showed $120^{\circ}$($90{\sim}150^{\circ}$) of forward flexion and $70^{\circ}$($10{\sim}90^{\circ}$) of external rotation before injection, and improved to $139^{\circ}$($135{\sim}140^{\circ}$) of forward flexion and $78^{\circ}$($50{\sim}90^{\circ}$) of external rotation after injection (p<0.01). VAS score improved from 7.1 (score 3~9) to 2.6 (score 0~5) (p<0.01) in perfect confinement group, from 7.5 (score 7~9) to 3.3 (score 2~4) (p<0.01) in partial leakage group. Two group showed no significant difference. Conclusion: Accuracy of Acromioclavicular approach was 94% which is better than any other methods published so far. Partial leakage of the injection material did not show inferior result compared to perfect injection.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.12
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• pp.1528-1534
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• 2004

The combination of ultrasound echo images with digital particle image velocimetry (DPIV) methods has resulted in a two-dimensional, two-component velocity field measurement technique appropriate for opaque flow conditions including blood flow in clinical applications. Advanced PIV processing algorithms including an iterative scheme and window offsetting were used to increase spatial resolution. The optimum concentration of the ultrasound contrast agent used for seeding was explored. Velocity validation tests in fully developed laminar pipe flow result of echo PIV showed good agreement with both optical PIV measurements and the known analytic solution based on a volume flow measurement.

• BT NEWS
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• v.17 no.1
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• pp.30-37
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• 2010

원문이미지 참조

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.1
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• pp.49-66
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• 2014

Traditionally, cervical interventions have been performed under fluoroscopy. But radiation exposure is the major concern when obtaining fluoroscopic images and even under real-time fluoroscopy with contrast media or CT guidance, some cases of serious spinal cord injuries, cerebellar and brain stem infarction have been reported by unintentional intra-arterial injections especially during the transforaminal root blocks. Recently, the use of ultrasound-guided cervical interventions have increased. Ultrasound offers visualization of soft tissues including major neurovascular structures and also allows to observe the spread of injectant materials around the target structure. Ultrasound is radiation free, easy to use and the image can be performed continuously while the injectant is visualized in real-time, increasing the precision of injection. Importantly, ultrasound allows visualization of major nerves and vessels and thus leads to improve safety of cervical interventions by decreasing the incidence of injury or injection into nearby vasculature. We therefore reviewed to investigate the feasibility of performing cervical interventions under real-time ultrasound guidance.

• Journal of radiological science and technology
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• v.32 no.2
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• pp.153-160
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• 2009

In this study, we investigated utility of ultrasonography for urinary tract infections of infants. The results of the research is as follows : 1. The number of infants under one year old was 100 out of 122 infants who were diagnosed as a unitary infection. The ratio of males to females was 1.7 : 1. Seventy-seven infants who underwent three kinds of radiologic examinations such as kidney sonography (51%), $^{99m}TC$ DMSA-scan (42%), and VCUG (22%). 2. In comparison of correlation between kidney sonography and VCUG, the sensitivity of kidney sonography was 82% while the specificity of kidney sonography was 58%. In comparison of correlation between kidney sonography and $^{99m}TC$ DMSA-scan, the sensitivity of kidney sonography was 66% while the specificity of kidney sonography was 67%. 3. Utility of kidney sonography showed the highest efficiency when we considered pain, discomfort, a sense of shame, psychological stress when infants may undergo at the examination, side-effect of a contrast agent after the examination, and complication of exposure to radiation.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.486-490
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• 2015

Two-demensional echocardiography is routinely used for evaluation of cardiac function. Visualization of the endocardial border is essential for the assessment of global and regional left ventricular with cardiac disease. SonoVue$^{TM}$ is a microbubble contrast agent that consists of sulfur hexafluoride-filled microbubbles in a phospholipid shell. There were many studies about contrast echocardiographic examination using SonoVue$^{TM}$ contrast agent, and various doses of SonoVue$^{TM}$ were used. To our knowledge, in published veterinary medicine, there was not reported for diagnostic efficient dose of SonoVue$^{TM}$ to evaluate contrast enhanced left ventricular endocardial border delineation (LVEBD). The purpose of this study is to compare the visualization time of LVEBD and find efficient dose of SonoVue$^{TM}$ for using various doses in dogs. Ten healthy Beagles were recruited to the study. Three different doses (0.03 ml/kg, 0.05 ml/kg and 0.1 ml/kg) of SonoVue$^{TM}$ were injected. Endocardial segments were assigned based on previously established methodology, where by the four-chamber views of the LV were divided into 6 segments. In this study, Contrast enhancement of the LVEBD after each injection was evaluated visually at the time point of overall contrast enhancement (Segmental scoring 5+) in the LV by three investigators in a blind manner. Statistical analysis was performed with SPSS version 14.0. All data were analyzed using one-way ANOVA, the multiple comparison Scheffe test. When data for the three offsite readers were combined, mean durations of useful contrast were $3.54({\pm}2.14)$, $6.15({\pm}2.61)$, and $24.39({\pm}11.10)$ seconds for the 0.03 ml/kg, 0.05 ml/kg, and 0.1 ml/kg SonoVue$^{TM}$ doses, respectively. After injection of contrast agent, there were no significant change in side effects such as urticaria, angioedema, hypersensitivity reactions, and digestive system disorders. This study suggests that efficient dose of SonoVue$^{TM}$ contrast agent for improvement of the left ventricle visualization is 0.1 ml/kg. The duration of useful enhancement of LVEBD and the reproducibility were also the highest at the 0.1 ml/kg dosage.