• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.11
• /
• pp.5682-5688
• /
• 2013

The purpose of this study is to maximize diagnositc usefulness with increasing signal to noise ratio(SNR) and contrast to noise ratio(CNR) by using a 1mmol/mL gadolinium contrast agent. From January 2012 to June 2013 fourty-seven patients were underwent the MRI scanning to investigate the contrast difference in gadolinium content. Twenty of the patients were injencted the commercial contrast agent containing 0.5mmol/mL gadolinium and the rest of them were injected the new contrast agent containing 1mmol/mL gadolinium called gadobutrol. We measured and evaluated each SNR and CNR of the hip joint space, iliopsoas muscle and femoral head. As a result, using the 1mmol/mL gadolinium contrast agent had the higher SNR results than using the 0.5mmol/mL agent(27% in the hip joint, 30.01% in the femoral head). Also CNR using the 1mmol/mL gadolinium agent was proved to be higher than that of using 0.5mmol/mL agent(28.31% in the ilopsoas muscle and 26.74% in the femoral head). Therefore, the contrast agent containing more gadolinium like 1mmol/mL used in this study is more effective to shorten T1 relaxation time, so it increases the signal intensity and CNR and furthermore maximizes diagnostic value. This study reports the usefulness of the 1mmol/mL contrast agent in the contrast-enhanced magnetic resonance hip arthrography for the first. Therefore, it can be considered to have an meaningful academic value as showing the method for increasing the diagnostic usefulness by using the 1mmol/mL contrast agent.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.12
• /
• pp.3654-3658
• /
• 2013

The synthesis of a DO3A conjugate of [(p-aniline benzothiazole)methyl]pyridine ($L^2H_3$) and its gadolinium complex of the type [$Gd(L^2)(H_2O)$] ($GdL^2$) is described. The $R_1$ relaxivity ($=4.50mM^{-1}sec^{-1}$) and kinetic inertness of $GdL^2$ compares well with those of structurally analogous Dotarem$^{(R)}$ ($R_1=3.70mM^{-1}sec^{-1}$), a typical extracellular (ECF) MRI contrast agent (CA). Yet, by comparison with Dotarem$^{(R)}$, $GdL^2$ exhibits non-covalent interactions with human serum albumin (HSA) as evidenced by the ${\varepsilon}^*$ titration curve along with in vivo MR signal enhancement in both aorta and heart. Liver-specific nature of $GdL^2$ is also observed as excretion is made through gallbladder. Most notably, $GdL^2$ further demonstrates specificity toward the MDA-MB-231 breast cancer.

• Investigative Magnetic Resonance Imaging
• /
• v.20 no.1
• /
• pp.75-79
• /
• 2016

We report a case of perivalvular abscess in a 66-year-old man with infective endocarditis, diagnosed by late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) imaging. No clinical features suspicious of infective endocarditis were noted, however, transthoracic echocardiography revealed non-specific echogenic focal wall thickening at mitral-aortic intervalvular fibrosa. Perivalvular abscess in the aortic valve was demonstrated as focal wall thickening between the anterior mitral leaflet and the non-coronary cusp of the aortic valve with peripheral enhancement and central low signal intensity on LGE CMR imaging. Other features suggestive of infective endocarditis, such as neither vegetation nor valvular perforation were present. The perivalvular abscess did not grow after intensive intravenous antibiotics therapy, and the patient was discharged without surgical treatment. CMR with LGE provided an early accurate diagnosis of perivalvular abscess. The diagnosis of perivalvular abscess using LGE CMR imaging was not previously reported in Korea.

• Journal of Powder Materials
• /
• v.21 no.3
• /
• pp.222-228
• /
• 2014

Much research into fuel cells operating at a temperature below $800^{\circ}C$. is being performed. There are significant efforts to replace the yttria-stabilized zirconia electrolyte with a doped ceria electrolyte that has high ionic conductivity even at a lower temperature. Even if the doped ceria electrolyte has high ionic conductivity, it also shows high electronic conductivity in a reducing environment, therefore, when used as a solid electrolyte of a fuel cell, the powergeneration efficiency and mechanical properties of the fuel cell may be degraded. In this study, gadolinium-doped ceria nanopowder with $Al_2O_3$ and $Mn_2O_3$ as a reinforcing and electron trapping agents were synthesized by ultrasonic pyrolysis process. After firing, their microstructure and mechanical and electrical properties were investigated and compared with those of pure gadolinium-doped ceria specimen.

• Journal of Korea Foundry Society
• /
• v.35 no.6
• /
• pp.163-169
• /
• 2015

This study reports the influence of gadolinium (Gd) addition on mechanical and corrosion properties of 2205 duplex stainless steel. In all alloys produced, regardless of the initial Gd content, Gd-based inclusions were well distributed in the duplex stainless steel matrix. As the Gd content increased from 0 wt% to 0.19 wt%, the ultimate tensile strength and hardness of the alloy increased from 630 MPa to 977 MPa and from 57 to 61, respectively, while elastic modulus, tensile elongation and impact energy of the alloy decreased. The critical crevice temperatures of Alloy1, Alloy2 and Alloy3 were $20^{\circ}C$, $20^{\circ}C$ and $15^{\circ}C$, respectively.

• Investigative Magnetic Resonance Imaging
• /
• v.20 no.2
• /
• pp.114-119
• /
• 2016

We report a case of vegetation in a 4-year-old female with infective endocarditis, diagnosed by late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) imaging. The patient had a history of primary closure for ventricular septal defect and presented with mild febrile sensation. No remarkable clinical symptoms or laboratory findings were noted; however, transthoracic echocardiography demonstrated a 14 mm highly mobile homogeneous mass in the right ventricle. On LGE CMR imaging, the mass showed marginal rim enhancement, which suggested the diagnosis of vegetation rather than thrombus. The extracellular volume fraction (${\geq}42%$) of the lesion was higher than that of normal myocardium. Based on the patient's clinical history of congenital heart disease and pathologic confirmation of the lesion, a diagnosis of infective endocarditis with vegetation was made.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.4
• /
• pp.849-852
• /
• 2009

The work describes EPR and 17O NMR measurements followed by theoretical calculation of the rotational correlation time $({\tau}_R)$, the water residence time $({\tau}_m)$, and the longitudinal electronic spin relaxation time $(T_{le})$(T_1e) for two new gadolinium complexes 1 and 2 of the type [$Gd(L)(H_2O)$] (L = tranexamic esters) in order to investigate their efficiency as a paramagnetic contrast agent (PCA). Of three correlation times, τR plays a major and predominant role to the unusually high relaxivity of 1 and 2 as compared with that of clinically approved MR CAs such as [$Gd(DTPA)(H_2O)]2‐ (Magnevist${\circledR}$), [Gd(DTPA-BMA)(H2O)] (Omniscan${\circledR}$), and $[Gd(DOTA)(H_2O)]^-$ (Dotarem${\circledR}$). The presence of bulky tranexamic ester in the ligand seems to be responsible for the conformational rigidity, which in turn causes such great an increase in ${\tau}_R$.

• Journal of radiological science and technology
• /
• v.24 no.2
• /
• pp.23-28
• /
• 2001

The purpose of this study is to compare the 3-dimensional MR angiography(MRA) with digital subtraction angiography(DSA) for the evaluation of pedal artery. MR angiography was performed using three-dimensional FISP acquisition before, and four sequential acquisitions after the injection of gadolinium(0.2 mmol/kg, 3 ml/sec). MRA was compared with DSA for a correct identification of the arterial segment. Out of 168 segments, 32 segmints were invisible in both MRA and DSA. At the level of ankle, 48 segments were visible in both examinations, and 18 segments were visible only in MRA. In the foot area, 34 segments were visible in MRA, but not in DSA. Three arterial segments were visible only in DSA. 3D MRA is comparable to DSA for the evaluation of pedal artery, thus it gives additional Information for the planning of treatment in lower extremity artery.

• Journal of the Korean Vacuum Society
• /
• v.12 no.4
• /
• pp.228-234
• /
• 2003

The velocity of gadolinium(Gd) atomic vapor vaporized by an electron beam was measured by a microbalance. The velocity of about 900 ㎧ was obtained at an evaporation surface temperature of 2400-2500 K. The measured value was approximately 100 ㎧ faster than the maximum velocity of an ideal monatomic gas in an adiabatic expansion. This phenomenon can be explained that the internal energy of Gd atoms populated in higher excited levels at the high temperature should be convened to kinetic energy during adiabatic expansion. The calculated velocity agrees with the measured one when 100 excited energy levels are included in an enthalpy term for the velocity calculation. The characteristics of vapor flow as a function of heated surface temperature are also reported.

• The Optical Journal
• /
• v.14 no.4 s.80
• /
• pp.71-73
• /
• 2002