• Title/Summary/Keyword: MRI 영상

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3-Dimensional Computed Tomography of Atlantoaxial Instability in Three Dogs (개에서 컴퓨터단층영상의 3차원 재구성을 통한 환축추골 아탈구 진단 3례)

  • Ahn, Se-Joon;Choi, Soo-Young;Lim, Soo-Ji;An, Ji-Young;Lee, In;Kwon, Young-Hang;Choi, Ho-Jung;Lee, Young-Won
    • Journal of Veterinary Clinics
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    • v.26 no.5
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    • pp.490-494
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    • 2009
  • A 2-year-old Maltese and a 5-month-old Yorkshire terrier were presented with ataxia. Tetraparesis was observed in a 9-year -old Yorkshire terrier. The localizations of the lesions suggested brain or cervical spinal cord by the neurological examination, and the following images was achieved: radiography, axial images of computed tomography (CT), reconstruction image of CT such as multi-planar reformation(MPR) and 3-dimensional(3D) reconstruction and magnetic resonance imaging (MRI). On radiography, the misalignment between atlas (C1) and axis (C2), absent dens of axis, and increased space between the dorsal arch of C1 and spinous process of C2 were found. The discontinuation between dens and body of C2 was identified through axial CT images, and the fragmentation of dens separated from axis was observed through MPR and 3D image in all case. The hyperintense lesions and the spinal cord compression on T2-weighted MR images were represented in a dog with tetraparesis, the others represented only spinal cord compression. Three dogs were diagnosed as atlantoaxial instability (AAI) by dens fracture of C2. The dog with tetraparesis was euthanized due to guarded prognosis. The others were recovered completely. It is difficult to differentiate dens fracture of C2 from abnormal dens such as agenesis and hypoplasia. We thought that CT is very useful to evaluate the dens of C2 and differentiate the causes of AAI, and the reconstruction images of CT such as MPR and 3D make the translation of the fragmented dens or axis of AAI more precisely evaluate.

Acute Type A Aortic Dissection Mimicking Penetrating Atherosclerotic Ulcer (침투성 동맥경화성 궤양과 흡사한 급성 A형 대동맥 박리증 -1l례 보고 -)

  • Choi, jae-Sung;Kwak, Jae-Gun;Ahn, Hyuk
    • Journal of Chest Surgery
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    • v.36 no.1
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    • pp.30-34
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    • 2003
  • As classical acute aortic dissection, atherosclerotic penetrating ulcers and intramural hematoma have different pathophysiology and natural history, treatment strategy should be different and, therefore, accurate differential diagnosis is necessary. However, these three aortic diseases may be indistinguishable by clinical observation and even by various diagnostic modalities such as cardiac echocardiography, CT and MRI. The patients was a 71-year-old female with chief complaints of anterior chest pain, nausea and vomiting which occurred suddenly 3 days before admission. CT angiographic with 3 dimensional reconstruction shows intramural hematoma in ascending aorta, aortic arch, descending thoracic aorta and right brachiocephalic trunk, heompericardium, and blood in mediastinum and both pleural cavities. The CT angiographic finding of focal out-bulging in the ascending thoracic aorta was diagnosed as penetrating atherosclerotic ulcer. The patient underwent emergency operation under a preoperative diagnosis of penetrating atherosclerotic ulcer with a sign of aortic rupture. In the intraoperative findings, however, intimal tear was seen in the anterior portion of the ascending aorta about 1cm below the brachiocephalic trunk and falselumen appeared after hematoma was removed from the layer of tunica media. We report a case of type A aortic dissection which mimicked clinical and diagnostic features of penetrating atherosclerotic ulcer.

Changes of Regional Homogeneity and Amplitude of Low Frequency Fluctuation on Resting-State Induced by Acupuncture (침자극에 의한 안정성 네트워크 변화를 관찰하기 위한 Regional Homogeneity와 Amplitude of Low Frequency Fluctuation의 변화 비교: fMRI연구)

  • Yeo, Sujung
    • Korean Journal of Acupuncture
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    • v.30 no.3
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    • pp.161-170
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    • 2013
  • Objectives : Our study aimed to investigate the sustained effects of sham (SHAM) and verum acupuncture (ACUP) into the post-stimulus resting state. Methods : In contrast to previous studies, in order to define the changes in resting state induced by acupuncture, changes were evaluated with a multi-method approach by using regional homogeneity (ReHo) and amplitude of low frequency fluctuation (ALFF). Twelve healthy participants received SHAM and ACUP stimulation right GB34 (Yanglingquan) and the neural changes between post- and pre-stimulation were detected. Results : The following results were found; in both ReHo and ALFF, the significant foci of; left and right middle frontal gyrus, left medial frontal gyrus, left superior frontal gyrus, and right posterior cingulate cortex, areas that are known as a default mode network, showed increased connectivity. In addition, in ReHo, but not in ALFF, brain activation changes in the insula, anterior cingulate cortex, and the thalamus, which are associated with acupuncture pain modulation, were found. Conclusions : In this study, results obtained by using ReHo and ALFF, showed that acupuncture can modulate the post-stimulus resting state and that ReHo, but not ALFF, can also detect the neural changes that were induced by the acupuncture stimulations. Although more future studies with ReHo and ALFF will be needed before any firm conclusions can be drawn, our study shows that particularly ReHo could be an interesting method for future clinical neuroimaging studies on acupuncture.

Evaluation of MR-SENSE Reconstruction by Filtering Effect and Spatial Resolution of the Sensitivity Map for the Simulation-Based Linear Coil Array (선형적 위상배열 코일구조의 시뮬레이션을 통한 민감도지도의 공간 해상도 및 필터링 변화에 따른 MR-SENSE 영상재구성 평가)

  • Lee, D.H.;Hong, C.P.;Han, B.S.;Kim, H.J.;Suh, J.J.;Kim, S.H.;Lee, C.H.;Lee, M.W.
    • Journal of Biomedical Engineering Research
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    • v.32 no.3
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    • pp.245-250
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    • 2011
  • Parallel imaging technique can provide several advantages for a multitude of MRI applications. Especially, in SENSE technique, sensitivity maps were always required in order to determine the reconstruction matrix, therefore, a number of difference approaches using sensitivity information from coils have been demonstrated to improve of image quality. Moreover, many filtering methods were proposed such as adaptive matched filter and nonlinear diffusion technique to optimize the suppression of background noise and to improve of image quality. In this study, we performed SENSE reconstruction using computer simulations to confirm the most suitable method for the feasibility of filtering effect and according to changing order of polynomial fit that were applied on variation of spatial resolution of sensitivity map. The image was obtained at 0.32T(Magfinder II, Genpia, Korea) MRI system using spin-echo pulse sequence(TR/TE = 500/20 ms, FOV = 300 mm, matrix = $128{\times}128$, thickness = 8 mm). For the simulation, obtained image was multiplied with four linear-array coil sensitivities which were formed of 2D-gaussian distribution and the image was complex white gaussian noise was added. Image processing was separated to apply two methods which were polynomial fitting and filtering according to spatial resolution of sensitivity map and each coil image was subsampled corresponding to reduction factor(r-factor) of 2 and 4. The results were compared to mean value of geomety factor(g-factor) and artifact power(AP) according to r-factor 2 and 4. Our results were represented while changing of spatial resolution of sensitivity map and r-factor, polynomial fit methods were represented the better results compared with general filtering methods. Although our result had limitation of computer simulation study instead of applying to experiment and coil geometric array such as linear, our method may be useful for determination of optimal sensitivity map in a linear coil array.

Soft-template Synthesis of Magnetically Separable Mesoporous Carbon (자성에 의해 분리 가능한 메조포러스 카본의 소프트 주형 합성)

  • Park, Sung Soo;Ha, Chang-Sik
    • Journal of Adhesion and Interface
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    • v.18 no.2
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    • pp.75-81
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    • 2017
  • In this study, we synthesized mesoporous carbon (Carbonized Ni-FDU-15) containing nanoporous structures and magnetic nanoparticles. Carbonized Ni-FDU-15 was synthesized via evaporation-induced self-assembly (EISA) and direct carbonization by using a triblock copolymer (F127) as a structure-directing agent, a resol precursor as a carbon-pore wall forming material, and nickel (II) nitrate as a metal ion source. The mesoporous carbon has a well-ordered two-dimensional hexagonal structure. Meanwhile, nickel (Ni) metal and nickel oxide (NiO) were produced in the magnetic nanoparticles in the pore wall. The size of the nanoparticles was about 37 nm. The surface area, pore size and pore volume of Carbonized Ni-FDU-15 were $558m^2g^{-1}$, $22.5{\AA}$ and $0.5cm^3g^{-1}$, respectively. Carbonized Ni-FDU-15 was found to move in the direction of magnetic force when magnetic force was externally applied. The magnetic nanoparticle-bearing mesoporous carbons are expected to have high applicability in a wide variety of applications such as adsorption/separation, magnetic storage media, ferrofluid, magnetic resonance imaging (MRI) and drug targeting, etc.

Cervical Transforaminal Axis Measured by MRI and Its Relation to the Internal Jugular Vein, Internal Carotid Artery and Vertebral Artery (자기공명영상장치를 이용해 측정한 경부 경추간공의 축과 내경정맥, 내경동맥, 척추동맥과의 관계 연구)

  • Kang, Sang Soo;Choi, Eun Seon;Park, Jun Hee;Hong, Seong Jun;Kim, Il Seok;Yun, Yeong Jun;Shin, Keun Man
    • The Korean Journal of Pain
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    • v.20 no.2
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    • pp.143-147
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    • 2007
  • Background: The safety of cervical transforaminal epidural block has been the subject of debate, therefore, this study was conducted to measure the angle of the cervical transforaminal axis and to investigate its relationship to the internal jugular vein, internal carotid artery and vertebral artery. Methods: One hundred cases of cervical MRI were reviewed. The angle between a line passing through the center of the vertebral body and spinous process and a line passing through the center of the lamina in C3-4, C4-5 and C5-6 was measured and designated as A-degree. Additionally, we drew a line at the back of the vertebral artery that ran parallel to a line passing through the center of the lamina, which was presented as A-line. We then examined the distribution of the area in which the internal jugular vein and the internal carotid artery were located. Results: The mean values of the A-degree in C3-4, C4-5 and C5-6 were $53.5{\pm}4.3$, $54.2{\pm}4.6$ and $54.3{\pm}4.8$, respectively. There were no statistically significant differences among age groups or vertebral levels (ANOVA test, P > 0.05). The A-line was distributed primarily throughout zone 3, 4, and 5 in C3-4 and zone 5 in C4-5 and C5-6. Conclusions: The results of this study indicate that the mean values of A-degree were not statistically different among each age group and each vertebral level. However, the A-line may be located in the zone in which the internal jugular vein and the internal carotid artery lie and individual differences in the A-degree remain.

Usefulness of contrast agent involving high gadolium content for myocardial viability assessment (심근생존능검사 시 가돌리늄 함유량이 높은 조영제의 유용성)

  • Choi, Kwan-Woo;Son, Soon-Yong;Kim, Tae-Hyung;Han, Man-Seok;Lee, Ju-Hee;Min, Jung-Whan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.3
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    • pp.1294-1300
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    • 2013
  • The purpose of this study is to increase contrast to noise ratio(CNR) in myocardial viability test by using contrast agent which highly content gadolinium(1mmol/mL) maximizing diagnostic value. This research method that four hundred four patients were underwent the MRI scanning two hundred eighty four of them were injected commercial contrast media which have 0.5mmol/L and the rest of them were injected new contrast media(gadobutrol) which have 1mmol/mL of molarity to study the contrast difference depending on the molarity of the contrast agent signal intensities of normal ventricle and left ventricle were measured to compare and evaluate signal to noise ratio(SNR) and CNR of the images. As result, 1mmol/mL contrast agent showed higher SNR by 25.13% in myocardium and 30.74% in left ventricle. CNR was proved to be better in 1mmol/mL contrast agent by 31.29%. The results above were all statistically meaningful. Therefore, contrast agent contenting more gadolinium which was 1mmol/mL in this study, could more effectively shorten T1 relaxation time, increase the signal intensity and at the same time maximize CNR and diagnostic value. This study firstly report the usefulness of 1mmol/mL contrast agent in patients allegedly suffering cardiac diseases and it is considered to increase diagnostic value.

Analysis of the Importance of Subjects to Improve the Educational Curriculum in the Radiological Science - Focused on Radiological Technologists - (방사선(학)과 교육과정 개선을 위한 교과목 중요도 분석 - 방사선사를 중심으로 -)

  • Kim, Jung-Hoon;Ko, Seong-Jin;Kang, Se-Sik;Kim, Dong-Hyun;Kim, Chang-Soo
    • Journal of radiological science and technology
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    • v.35 no.2
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    • pp.125-132
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    • 2012
  • In this study a group of experts and clinical radiological technologists were surveyed to evaluate the clinical importance of current subjects in the radiological sciences. For the data collection and analysis, an open-ended questionnaire was distributed to the group of experts, and a multiple choice questionnaire was distributed to radiological technologists. Subjects were classified into 9 groups for analysis of the importance of subjects, and in regard to the questionnaire design for measurement of variables, departments and type of hospital were set up as independent variables, and the 9 groups of subjects were set up as dependent variables. As a result, clinical radiological technologists perceived Diagnostic Imaging Technology and practical courses, including general radiography, CT and MRI, as the most clinically necessary subjects, and the group of experts placed most weight on basic courses for the major. The result of this study suggests that the curriculum should be revised in a way that combines theory and practice in order to foster radiological technologists capable of adapting to the rapidly changing healthcare environment.

Ex Vivo MR Diffusion Coefficient Measurement of Human Gastric Tissue (인체의 위 조직 시료에서 자기공명영상장치를 이용한 확산계수 측정에 대한 기초 연구)

  • Mun Chi-Woong;Choi, Ki-Sueng;Nana Roger;Hu, Xiaoping P.;Yang, Young-Il;Chang Hee-Kyung;Eun, Choong-Ki
    • Journal of Biomedical Engineering Research
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    • v.27 no.5
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    • pp.203-209
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    • 2006
  • The aim of this study is to investigate the feasibility of ex vivo MR diffusion tensor imaging technique in order to observe the diffusion-contrast characteristics of human gastric tissues. On normal and pathologic gastric tissues, which have been fixed in a polycarbonate plastic tube filled with 10% formalin solution, laboratory made 3D diffusion tensor Turbo FLASH pulse sequence was used to obtain high resolution MR images with voxel size of $0.5{\times}0.5{\times}0.5mm^3\;using\;64{\times}32{\times}32mm^3$ field of view in conjunction with an acquisition matrix of $128{\times}64{\times}64$. Diffusion weighted- gradient pulses were employed with b values of 0 and $600s/mm^2$ in 6 orientations. The sequence was implemented on a clinical 3.0-T MRI scanner(Siemens, Erlangen, Germany) with a home-made quadrature-typed birdcage Tx/Rx rf coil for small specimen. Diffusion tensor values in each pixel were calculated using linear algebra and singular value decomposition(SVD) algorithm. Apparent diffusion coefficient(ADC) and fractional anisotropy(FA) map were also obtained from diffusion tensor data to compare pixel intensities between normal and abnormal gastric tissues. The processing software was developed by authors using Visual C++(Microsoft, WA, U.S.A.) and mathematical/statistical library of GNUwin32(Free Software Foundation). This study shows that 3D diffusion tensor Turbo FLASH sequence is useful to resolve fine micro-structures of gastric tissue and both ADC and FA values in normal gastric tissue are higher than those in abnormal tissue. Authors expect that this study also represents another possibility of gastric carcinoma detection by visualizing diffusion characteristics of proton spins in the gastric tissues.

The Value of Preoperative MRI and Bone Scan in Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures (골다공증성 척추체 압박골절에 대한 경피적 척추성형술시 자기공명영상과 골 주사 검사의 의의)

  • Kim, Se Hyuk;Lee, Wan Su;Seo, Eui Kyo;Shin, Yong Sam;Zhang, Ho Yeol;Jeon, Pyoung
    • Journal of Korean Neurosurgical Society
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    • v.30 no.7
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    • pp.907-915
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    • 2001
  • Objective : Percutaneous vertebroplasty is often complicated by the presence of multiple fractures or non-localizing pain in the patients with osteoporotic vertebral fractures. The purpose of this study is to estimate the value of preoperative radiologic studies in the localization of symptomatic vertebrae and to determine the factors which can influence on the clinical results. Materials and Methods : We retrospectively reviewed the clinical and radiologic data of 57 vertebrae in 30 patients underwent percutaneous vertebroplasty for osteoporotic vertebral compression fractures. Inclusion criteria was severe pain(McGill-Melzack score 3, 4 or 5) associated with the acute vertebral fractures and absence of spinal nerve root or cord compression sign. Acute symptomatic vertebral fracture was determined by the presence of signal change on MR images or increased uptake on whole body bone scan. Results : Pain improvement was obtained immediately in all patients and favorable result was sustained in 26 patients(86.7%) during the mean follow-up duration of 4.7 months(5 complete pain relief, 21 marked pain relief). Those who underwent vertebroplasty for all acute symptomatic vertebrae had significantly better clinical result than those who did not. Further vertebral collapse and eventual bursting fracture occurred in 1 vertebra which showed intradiskal leakage of bone cement and disruption of cortical endplate on postoperative CT scan. Conclusion : Preoperative MR imaging and whole body bone scan are very useful in determining the symptomatic vertebrae, especially in the patients with multiple osteoporotic vertebral fractures. To obtain favorable clinical result, the careful radiologic evaluation as well as clinical assessment is required. Control of PMMA volume seems to be the most critical point for avoiding complications.

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