The aim of this study was to compare differences in imaging quality at different injection rates of gadobutrol(Gadovist? 1.0M) for dynamic supra-aortic imaging by contrast-enhanced magnetic resonance angiography(CEM R...The aim of this study was to compare differences in imaging quality at different injection rates of gadobutrol(Gadovist? 1.0M) for dynamic supra-aortic imaging by contrast-enhanced magnetic resonance angiography(CEM RA). In 6 healthy volunteers,dynamic CEM RA examinations were performed twice at a 7 d interval with a gadobutrol dose of 0.1 mmol given to 1 kg body mass. For the two examinations,the contrast medium was injected at rates of 1.5 mL/s and 2.0 mL/s,followed by 20 mL normal saline injected at the same rate. Using a GE Signa 3.0T M R apparatus and the time-resolved imaging of contrast kinetics(TRICKS) technique,scanning was performed continuously for 15 phases at a time resolution of about 2.4 s. Vascular reconstruction was undertaken by multiplane reconstruction and maximum intensity projection techniques. Two radiologists experienced in CEM RA diagnosis subjectively evaluated the contrast effect,vascular detail,and pseudo-shadow of all images,and graded them via a 5-point scale. With the two drug injection rates,the image quality,peak signal-to-noise ratio(SNR) and contrast-to-noise ratio(CNR) were compared for imaging of the infra-aortic arch,brachiocephalic trunk,subclavian artery(left/right),common carotid artery(left/right),internal carotid artery(left/right),and external carotid artery(left/right). Characteristics of the time-signal-intensity(T-S-I) curves were also analyzed at the two injection rates. All studies were performed successfully,without any complications. There was good image quality with both gadobutrol injection rates of 1.5 mL/s and 2.0 mL/s,and subjective scores for image quality,SNR and CNR were not significantly different between the two rates(P > 0.05). The time-to-peak(TTP) from the hand dorsal vein injection site to the carotid artery ranged from 16.0 s to 27.1 s(mean 21.7 s ±3.4 s) in the 6 subjects,and was also not significantly different between the two drug injection rates(P > 0.05). We conclude that dynamic CEM RA examination of the supra-aortic arch with gadobutrol injection at a rate of 1.5 mL/s was feasible,and satisfactorily reflected vascular shape and dynamic blood flow information.展开更多
MRI is an indispensable diagnostic tool in modern medicine;however,understanding the molecular-level processes governing NMR relaxation of water in the presence of MRI contrast agents remains a challenge,hindering the...MRI is an indispensable diagnostic tool in modern medicine;however,understanding the molecular-level processes governing NMR relaxation of water in the presence of MRI contrast agents remains a challenge,hindering the molecularguided development of more effective contrast agents.By using quantum-based polarizable force fields,the first-of-its-kind molecular dynamics(MD)simulations of Gadobutrol are reported where the ^(1)H NMR longitudinal relaxivity r_(1) of the aqueous phase is determined without any adjustable parameters.The MD simulations of r_(1) dispersion(i.e.,frequency dependence)show good agreement with measurements at frequencies of interest in clinical MRI.Importantly,the simulations reveal key insights into the molecular level processes leading to r_(1) dispersion by decomposing the NMR dipole−dipole autocorrelation function G(t)into a discrete set of molecular modes,analogous to the eigenmodes of a quantum harmonic oscillator.The molecular modes reveal important aspects of the underlying mechanisms governing r_(1),such as its multiexponential nature and the importance of the second eigenmodal decay.By simply analyzing the MD trajectories on a parameter-free approach,the Gadobutrol simulations show that the outer-shell water contributes∼50%of the total relaxivity r_(1) compared to the inner-shell water,in contrast to simulations of(nonchelated)gadolinium-aqua where the outer shell contributes only∼15%of r_(1).The deviation between simulations and measurements of r_(1) below clinical MRI frequencies is used to determine the low-frequency electron-spin relaxation time for Gadobutrol,in good agreement with independent studies.展开更多
Objective To present a rare case of skin allergic reaction to gadobutrol,a magnetic resonance imaging(MRI)contrast agent,in a 37-year-old man.Methods The adverse reactions of gadobutrol were analyzed combined with the...Objective To present a rare case of skin allergic reaction to gadobutrol,a magnetic resonance imaging(MRI)contrast agent,in a 37-year-old man.Methods The adverse reactions of gadobutrol were analyzed combined with the instructions and related literatures.Results and Conclusion The presence of this patient is consistent with the adverse reactions in the instructions of gadobutrol.The incidence of ADR in gadobutrol is considered to be low,although sometimes patients report a hypersensitivity reaction when undergoing MRI.There are only a few cases of immediate adverse reactions to gadobutrol.However,we should improve the ability of medical staff to use drugs safely and take preventive measures.展开更多
文摘The aim of this study was to compare differences in imaging quality at different injection rates of gadobutrol(Gadovist? 1.0M) for dynamic supra-aortic imaging by contrast-enhanced magnetic resonance angiography(CEM RA). In 6 healthy volunteers,dynamic CEM RA examinations were performed twice at a 7 d interval with a gadobutrol dose of 0.1 mmol given to 1 kg body mass. For the two examinations,the contrast medium was injected at rates of 1.5 mL/s and 2.0 mL/s,followed by 20 mL normal saline injected at the same rate. Using a GE Signa 3.0T M R apparatus and the time-resolved imaging of contrast kinetics(TRICKS) technique,scanning was performed continuously for 15 phases at a time resolution of about 2.4 s. Vascular reconstruction was undertaken by multiplane reconstruction and maximum intensity projection techniques. Two radiologists experienced in CEM RA diagnosis subjectively evaluated the contrast effect,vascular detail,and pseudo-shadow of all images,and graded them via a 5-point scale. With the two drug injection rates,the image quality,peak signal-to-noise ratio(SNR) and contrast-to-noise ratio(CNR) were compared for imaging of the infra-aortic arch,brachiocephalic trunk,subclavian artery(left/right),common carotid artery(left/right),internal carotid artery(left/right),and external carotid artery(left/right). Characteristics of the time-signal-intensity(T-S-I) curves were also analyzed at the two injection rates. All studies were performed successfully,without any complications. There was good image quality with both gadobutrol injection rates of 1.5 mL/s and 2.0 mL/s,and subjective scores for image quality,SNR and CNR were not significantly different between the two rates(P > 0.05). The time-to-peak(TTP) from the hand dorsal vein injection site to the carotid artery ranged from 16.0 s to 27.1 s(mean 21.7 s ±3.4 s) in the 6 subjects,and was also not significantly different between the two drug injection rates(P > 0.05). We conclude that dynamic CEM RA examination of the supra-aortic arch with gadobutrol injection at a rate of 1.5 mL/s was feasible,and satisfactorily reflected vascular shape and dynamic blood flow information.
基金Ken Kennedy Institute,the Rice University Creative Ventures Fund(Faculty Initiatives Fund)the Robert A.Welch Foundation for the financial support.
文摘MRI is an indispensable diagnostic tool in modern medicine;however,understanding the molecular-level processes governing NMR relaxation of water in the presence of MRI contrast agents remains a challenge,hindering the molecularguided development of more effective contrast agents.By using quantum-based polarizable force fields,the first-of-its-kind molecular dynamics(MD)simulations of Gadobutrol are reported where the ^(1)H NMR longitudinal relaxivity r_(1) of the aqueous phase is determined without any adjustable parameters.The MD simulations of r_(1) dispersion(i.e.,frequency dependence)show good agreement with measurements at frequencies of interest in clinical MRI.Importantly,the simulations reveal key insights into the molecular level processes leading to r_(1) dispersion by decomposing the NMR dipole−dipole autocorrelation function G(t)into a discrete set of molecular modes,analogous to the eigenmodes of a quantum harmonic oscillator.The molecular modes reveal important aspects of the underlying mechanisms governing r_(1),such as its multiexponential nature and the importance of the second eigenmodal decay.By simply analyzing the MD trajectories on a parameter-free approach,the Gadobutrol simulations show that the outer-shell water contributes∼50%of the total relaxivity r_(1) compared to the inner-shell water,in contrast to simulations of(nonchelated)gadolinium-aqua where the outer shell contributes only∼15%of r_(1).The deviation between simulations and measurements of r_(1) below clinical MRI frequencies is used to determine the low-frequency electron-spin relaxation time for Gadobutrol,in good agreement with independent studies.
文摘Objective To present a rare case of skin allergic reaction to gadobutrol,a magnetic resonance imaging(MRI)contrast agent,in a 37-year-old man.Methods The adverse reactions of gadobutrol were analyzed combined with the instructions and related literatures.Results and Conclusion The presence of this patient is consistent with the adverse reactions in the instructions of gadobutrol.The incidence of ADR in gadobutrol is considered to be low,although sometimes patients report a hypersensitivity reaction when undergoing MRI.There are only a few cases of immediate adverse reactions to gadobutrol.However,we should improve the ability of medical staff to use drugs safely and take preventive measures.
