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C. Kessler - One of the best experts on this subject based on the ideXlab platform.
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Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques--frequency- or power-based Doppler and contrast enhancement.
Neuroradiology, 1998Co-Authors: B. Griewing, U. Schminke, L. Motsch, F. Brassel, C. KesslerAbstract:The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30 % of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml Shu 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7 % higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20 % higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9 %) could not be shown using TCCD.
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Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques – frequency- or power-based Doppler and contrast enhancement
Neuroradiology, 1998Co-Authors: B. Griewing, U. Schminke, L. Motsch, F. Brassel, C. KesslerAbstract:The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30 % of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml Shu 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7 % higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20 % higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9 %) could not be shown using TCCD.
Harald Becher - One of the best experts on this subject based on the ideXlab platform.
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Shu 508 A (Levovist)‐Enhanced Doppler Echocardiography Improves the Assessment of Valvular Heart Disease
Echocardiography (Mount Kisco N.Y.), 2001Co-Authors: Wolfgang Lepper, Andreas Franke, Helene Von Bibra, Harald Becher, Kerstin Holz, M. Näbauer, Zvi Vered, Rainer Hoffmann, Frank A. Flachskampf, Peter HanrathAbstract:Objective: To investigate whether intravenous injection of Shu 508 A improves the diagnostic accuracy of Doppler echocardiography in the assessment of valvular pathologies. Methods and Results: One hundred and twenty-five consecutive patients with valvular pathology (aortic stenosis, n = 48; aortic regurgitation, n = 20; mitral stenosis, n = 21; and mitral regurgitation, n = 36) and diagnostically insufficient Doppler signal were enrolled in this multicenter study. The severity of valvular pathology was graded on a four-point scale using unenhanced and contrast-enhanced Doppler echocardiography as well as cardiac catheterization. Agreement with cardiac catheterization findings increased from 63% using the unenhanced examination to 73% using the contrast-enhanced Doppler examination. Grading was possible in all patients using Shu 508 A, whereas the unenhanced Doppler examination remained inconclusive in six patients. The weighted kappa coefficient between contrast-enhanced Doppler and cardiac catheterization for all diagnoses was 0.76 as compared to 0.68 between unenhanced Doppler and cardiac catheterization. Agreement was especially improved in aortic stenosis (kappa 0.69 unenhanced vs 0.81 contrast-enhanced) and in aortic regurgitation (kappa 0.45 unenhanced vs 0.75 contrast-enhanced). Patients with mitral stenosis and mitral regurgitation experienced less improvement. Conclusions: In case of an inconclusive unenhanced Doppler echo study, the administration of a left heart contrast agent should be considered. Shu 508 A is especially useful in improving the severity grading of aortic stenosis and aortic regurgitation, while grading of mitral stenosis and mitral regurgitation is less improved.
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Stimulated acoustic emission detected by transcranial color doppler ultrasound : a contrast-specific phenomenon useful for the detection of cerebral tissue perfusion.
Stroke, 2000Co-Authors: Christoph Pohl, Klaus Tiemann, Thomas Schlosser, Harald BecherAbstract:Background and Purpose—Experimental and clinical data suggest that insonation of echo-contrast agents with high acoustical power produces disintegration of microbubbles, resulting in a pseudo-Doppler phenomenon called stimulated acoustic emission (SAE). The purpose of this study was to investigate whether SAE might be detected by transcranial color Doppler imaging and whether these signals might be used for cerebral tissue perfusion measurements. Methods—Nonmoving microbubbles (Shu 563 A) were insonated in vitro through the temporal parts of a human cadaver skull, and contrast signals were detected by velocity-coded color Doppler and power Doppler recordings. Transcranial color as well as power Doppler investigations were performed in 10 healthy volunteers with the echo-contrast agent Levovist (Shu 508 A). Results—Color Doppler signals indicating SAE were observed in vitro and in transcranial human investigations. These signals were characterized by a mosaic of color Doppler pixels ranging over the full c...
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Enhancement of mitral regurgitation and normal left atrial color Doppler flow signals with peripheral venous injection of a saccharide-based contrast agent.
Journal of the American College of Cardiology, 1993Co-Authors: Hellen Von Bibra, Harald Becher, Reinhard Schlief, Christian Firschke, H.-p. Emslander, Albert SchömigAbstract:Abstract Objectives . The saccharide ultrasound contrast agent Shu 508 A was used to test the hypothesis that an intravenous, transpulmonary contrast method can enhance color Doppler flow signals in the left atrium in a clinically useful manner. Background . Color Doppler display of mitral regurgiation may be unreliable because of variable signal to noise ratios that are at times poor. Traditional contrast agents enhance color Doppler flow signals in the right heart chambers. This study describes our observation of a recently developed contrast agent, Shu 508 A, capable of pulmonary transit after peripheral venous injection. Methods . Control subjects (n = 10) and patients with suspected mitral regurgitation (n = 23) were studied by color Doppler flow imaging before and after 3-g intravenous doses of Shu 508 A. Reference grading of mitral regurgitation (0 to 3) was formulated from left ventricular angiography. In the four-chamber view of the left atrium, we selected for analysis the systolic frame with the maximal retrograde jet of mitral regurgitation (aliased/blue) and the diastolic frame with the maximal color coding from anterograde pulmonary venous flow (red) for planimetry and for grading the intensity of the color Doppler signal (0 to 5). Results . The score of the color Doppler signal intensity increased by ≥2.5 after 3 g of Shu 508 A (p 2 , p Conclusions . Contrast-mediated incresed echogenicity of the left atrial blood pool improves the signals to noise ratio of Doppler images of mitral regurgitation and anterograde atrial flow. The technique is safe and simple and seems to minimize variability due to instrument design and anatomic signals attenuation.
B. Griewing - One of the best experts on this subject based on the ideXlab platform.
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Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques--frequency- or power-based Doppler and contrast enhancement.
Neuroradiology, 1998Co-Authors: B. Griewing, U. Schminke, L. Motsch, F. Brassel, C. KesslerAbstract:The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30 % of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml Shu 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7 % higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20 % higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9 %) could not be shown using TCCD.
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Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques – frequency- or power-based Doppler and contrast enhancement
Neuroradiology, 1998Co-Authors: B. Griewing, U. Schminke, L. Motsch, F. Brassel, C. KesslerAbstract:The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30 % of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml Shu 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7 % higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20 % higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9 %) could not be shown using TCCD.
Haraldbecher - One of the best experts on this subject based on the ideXlab platform.
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Stimulated Acoustic Emission Detected by Transcranial Color Doppler Ultrasound
Stroke, 2000Co-Authors: Christophpohl, Klaustiemann, Thomasschlosser, HaraldbecherAbstract:Background and Purpose—Experimental and clinical data suggest that insonation of echo-contrast agents with high acoustical power produces disintegration of microbubbles, resulting in a pseudo-Doppler phenomenon called stimulated acoustic emission (SAE). The purpose of this study was to investigate whether SAE might be detected by transcranial color Doppler imaging and whether these signals might be used for cerebral tissue perfusion measurements. Methods—Nonmoving microbubbles (Shu 563 A) were insonated in vitro through the temporal parts of a human cadaver skull, and contrast signals were detected by velocity-coded color Doppler and power Doppler recordings. Transcranial color as well as power Doppler investigations were performed in 10 healthy volunteers with the echo-contrast agent Levovist (Shu 508 A). Results—Color Doppler signals indicating SAE were observed in vitro and in transcranial human investigations. These signals were characterized by a mosaic of color Doppler pixels ranging over the full c...
F. Brassel - One of the best experts on this subject based on the ideXlab platform.
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Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques--frequency- or power-based Doppler and contrast enhancement.
Neuroradiology, 1998Co-Authors: B. Griewing, U. Schminke, L. Motsch, F. Brassel, C. KesslerAbstract:The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30 % of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml Shu 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7 % higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20 % higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9 %) could not be shown using TCCD.
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Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques – frequency- or power-based Doppler and contrast enhancement
Neuroradiology, 1998Co-Authors: B. Griewing, U. Schminke, L. Motsch, F. Brassel, C. KesslerAbstract:The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30 % of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml Shu 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7 % higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20 % higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9 %) could not be shown using TCCD.
