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Marc-andré Weber - One of the best experts on this subject based on the ideXlab platform.
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Contrast-Enhanced Ultrasound Determines Supraspinatus Muscle Atrophy After Cuff Repair and Correlates to Functional Shoulder Outcome.
American Journal of Sports Medicine, 2018Co-Authors: Christian Fischer, Sascha Gross, Felix Zeifang, Gerhard Schmidmaier, Marc-andré Weber, Pierre KunzAbstract:Background:Muscle degeneration as a consequence of rotator cuff tears is mainly assessed by magnetic resonance imaging. Contrast-enhanced ultrasound (CEUS) is a new functional imaging method to assess microvascular Perfusion as a fundamental parameter of Muscle tissue vitality. In this cross-sectional study, the authors evaluated supraspinatus Muscle Perfusion after cuff repair and analyzed its association with functional shoulder outcome and the grade of echogenicity in B-mode ultrasound indicating fatty infiltration.Hypothesis:The authors expected reduced microPerfusion of the operated versus the contralateral supraspinatus Muscle and a correlation of the muscular microPerfusion with functional shoulder outcome.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Patients who received unilateral repair of the supraspinatus tendon between 2009 and 2014 were invited for a single follow-up examination. Functional scores were assessed, including the Constant-Murley score and American Shoulder an...
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Comparison of transient arterial occlusion and Muscle exercise provocation for assessment of Perfusion reserve in skeletal Muscle with real-time contrast-enhanced ultrasound
European Journal of Radiology, 2011Co-Authors: Martin Krix, Holger Krakowski-roosen, Erick Armarteifio, Susanne Fürstenberger, Stefan Delorme, Hans-ulrich Kauczor, Marc-andré WeberAbstract:Abstract Objective Contrast-enhanced ultrasound (CEUS) is able to quantify Muscle Perfusion and changes in Perfusion due to Muscle exercise in real-time. However, reliable measurement of standardized Muscle exercise is difficult to perform in clinical examinations. We compared Perfusion reserve assessed by CEUS after transient arterial occlusion and exercise to find the most suitable measurement for clinical application. Methods Contrast pulse sequencing (7 MHz) during continuous IV infusion of SonoVue® (4.8 mL/300 s) was used in 8 healthy volunteers to monitor Muscle Perfusion of the gastrocnemius Muscle during transient (1 min) arterial occlusion produced by a thigh cuff of a venous occlusion plethysmograph. Isometric Muscle exercise (50% of individual maximum strength for 20 s) was subsequently performed during the same examination, and several CEUS parameters obtained from ultrasound-signal-intensity–time curves and its calculation errors were compared. Results The mean maximum local blood volume after occlusion was 13.9 [∼mL] (range, 4.5–28.8 [∼mL]), and similar values were measured after sub-maximum exercise 13.8 [∼mL], (range, 4.6–22.2 [∼mL]. The areas under the curve during rePerfusion vs. recovery were also similar (515.2 ± 257.5 compared to 482.2 ± 187.5 [∼mL s]) with a strong correlation (r = 0.65), as were the times to maximum (15.3 s vs. 15.9 s), with a significantly smaller variation for the occlusion method (±2.1 s vs. ±9.0 s, p = 0.03). The mean errors for all calculated CEUS parameters were lower for the occlusion method than for the exercise test. Conclusions CEUS Muscle Perfusion measurements can be easily performed after transient arterial occlusion. It delivers data which are comparable to CEUS measurements after Muscle exercise but with a higher robustness. This method can be easily applied in clinical examination of patients with e.g. PAOD or diabetic microvessel diseases to assess Perfusion reserve.
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real time contrast enhanced ultrasound for the assessment of Perfusion dynamics in skeletal Muscle
Ultrasound in Medicine and Biology, 2009Co-Authors: Martin Krix, Marc-andré Weber, Stefan Delorme, Hans-ulrich Kauczor, Holger KrakowskiroosenAbstract:We developed a real-time low-MI contrast-enhanced ultrasound method (CEUS), compared it with venous occlusion plethysmography (VOP) and evaluated its robustness in the quantification of skeletal Muscle Perfusion during exercise. Contrast pulse sequencing (7 MHz) during continuous intravenous infusion of SonoVue (4.8 mL/300 s) was used repeatedly in eight healthy volunteers to monitor changes of the Muscle Perfusion before, during and after isometric exercises (10 to 50% of individual maximum strength for 20 to 30 s) of the gastrocnemius Muscle in real time. CEUS was correlated with VOP at different time points, and the exactness of several CEUS parameters obtained from ultrasound-signal-intensity-time curves was evaluated. Real-time CEUS depicted a large variability of the skeletal Muscle blood volume at rest (mean, 3.48; range, 0.60 to 9.92 [approximately mL]), with a significant reproducibility (r=0.72, p<0.05) and correlation with VOP (r=0.59, p<0.001). Mean blood volume during exercise was 1.58(approximately mL), increased to a mean maximum after exercise of 8.88 (approximately mL), the mean change of the local blood volume during and directly after the exercise was -0.10 and +1.57(approximately mL/s). The average CEUS signal during exercise decreased (mean area under the curve, -50.4 [approximately mL.s]) and subsequently increased post exercise (mean 118.6 [approximately mL.s]). CEUS parameters could be calculated with mean relative errors between 6 and 36%. Continuous assessment of local Muscle microcirculation during exercise is possible with real-time CEUS with an acceptable robustness. Its application may be of particular interest in a better understanding of the role of Perfusion during Muscle training, and the monitoring of pathological vascular response, such as in diabetic microvessel diseases.
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quantitative evaluation of Muscle Perfusion with ceus and with mr
European Radiology, 2007Co-Authors: Marc-andré Weber, Martin Krix, Stefan DelormeAbstract:Functional imaging might increase the role of imaging in muscular diseases, since alterations of Muscle morphology alone are not specific for a particular disease. Perfusion, i.e., the blood flow per tissue and time unit including capillary flow, is an important functional parameter. Pathological changes of skeletal Muscle Perfusion can be found in various clinical conditions, such as degenerative or inflammatory myopathies or peripheral arterial occlusive disease. This article reviews the theoretical basics of functional radiological techniques for assessing skeletal Muscle Perfusion and focuses on contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI) techniques. Also, the applications of microvascular imaging, such as in detection of myositis and for discriminating myositis from other myopathies or evaluating peripheral arterial occlusive disease, are presented, and possible clinical indications are discussed. In conclusion, dedicated MR and CEUS methods are now available that visualize and quantify (patho-)physiologic information about microcirculation within skeletal Muscles in vivo and hence establish a useful diagnostic tool for muscular diseases.
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relationship of skeletal Muscle Perfusion measured by contrast enhanced ultrasonography to histologic microvascular density
Journal of Ultrasound in Medicine, 2006Co-Authors: Marc-andré Weber, Martin Krix, Stefan Delorme, Hans-ulrich Kauczor, Holger Krakowskiroosen, Hanna Renk, Juan Millies, Ralf Kinscherf, Annette Kunkele, Wulf HildebrandtAbstract:OBJECTIVE The purpose of this study was to compare skeletal Muscle Perfusion measured by contrast-enhanced ultrasonography (CEUS) with microvascular density in Muscle biopsies. METHODS Power Doppler sonography after intravenous bolus injection of Levovist (SH U 508A; Schering AG, Berlin, Germany) was used to examine Perfusion of vastus lateralis Muscle in 23 healthy volunteers. Local blood volume (B), blood flow velocity (v), and blood flow (f) were calculated by analyzing replenishment kinetics. CEUS Perfusion was compared with vascularization of biopsy samples from vastus lateralis Muscle. Subjects were selected such that their aerobic capacity (maximal oxygen uptake [VO(2)max]) per body weight ranged between 23 and 66 mL . min(-1) . kg(-1) to render a large variability of skeletal Muscle capillarization. Moreover, subjects' venous blood hematocrit (Hkt) was determined to estimate the plasmatic intravascular volume fraction (1-Hkt=PVF) in which the microbubbles can distribute. RESULTS Median capillary density was 331/mm(2) (range, 207-469/mm(2)), and median capillary fiber contacts (CFC) were 3.6 (range, 2.3-6.5). CFC was correlated with VO(2)max (r=0.59; P<.01). Among CEUS parameters, B showed the closest correlation to CFC (r=0.53; P<.01). When CFC was normalized for PVF, correlation of B to CFC was r=0.64 (P<.01). CEUS could depict the physiologic large variability of vastus lateralis Muscle Perfusion at rest (median [range]: B, 2.5 [0.1-12.3] approximately mL; v, 0.3 [0.1-3.7] mm/s; f, 0.7 [0.1-5.3] approximately mL . min(-1) . 100 g tissue(-1)). CONCLUSIONS B is significantly related to fiber-adjacent capillarization and may represent physiologic capillary recruitment (eg, through metabolic fiber-related signals). CEUS is feasible for skeletal Muscle Perfusion quantification.
Jefferson C Frisbee - One of the best experts on this subject based on the ideXlab platform.
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Running Head: Metabolic syndrome and skeletal Muscle Perfusion Send Correspondence to:
2016Co-Authors: Jefferson C FrisbeeAbstract:This study tested the hypothesis that chronically elevated oxidant stress contributes to impaired active hyperemia in skeletal Muscle of obese Zucker rats (OZR) versus lean Zucker rats (LZR) through progressive deteriorations in microvascular structure. 12-week old LZR and OZR were given 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPOL) in the drinking water for ~4 weeks. Subsequently, Perfusion of in situ gastrocnemius Muscle was determined during incremental elevations in metabolic demand, while a contralateral skeletal Muscle arteriole and the gastrocnemius Muscle was removed to determine dilator reactivity, vessel wall mechanics, and microvessel density. Under control conditions, active hyperemia was impaired at all levels of metabolic demand in OZR, and this was correlated with a reduced microvessel density, increased arteriolar stiffness and impaired dilator reactivity. Chronic TEMPOL ingestion improved Perfusion during moderate to high metabolic demand only, and was associated with improved arteriolar reactivity and microvessel density; passive vessel mechanics were unaltered. Combined antioxidant therapy and nitric oxide synthase inhibition in OZR prevented much of the restored Perfusion and microvessel density. In LZR, treatment with Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) and hydralazine (to prevent hypertension) impaire
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vascular function in the metabolic syndrome and the effects on skeletal Muscle Perfusion lessons from the obese zucker rat
Essays in Biochemistry, 2006Co-Authors: Jefferson C Frisbee, Michael D DelpAbstract:The increased prevalence of obesity in Western society has been well established for many years, and with this trend, the prevalence of other associated pathologies including insulin resistance, dyslipidaemia, hypertension and the genesis of a proinflammatory and prothrombotic environment within individuals is also rapidly increasing, resulting in a condition known as the~metabolic syndrome. From a physiological perspective, one of the most severe consequences of the metabolic syndrome is a progressive inability of the cardiovascular system to adequately perfuse tissues and organs during either elevated metabolic demand and, if sufficiently severe, under basal levels of demand. For the study of the metabolic syndrome, the OZR (obese Zucker rat) represents an important tool in this effort, as the metabolic syndrome in these animals results from a chronic hyperphagia, and thus can be an excellent representation of the human condition. As in afflicted humans, OZR experience an attenuated functional and reactive hyperaemia, and can ultimately experience an ischaemic condition in their skeletal Muscles at rest. The source of this progressive ischaemia appears to lie at multiple sites, as endothelium-dependent vasodilator responses are strongly impaired in OZR, and specific constrictor processes (e.g. adrenergic tone) may be enhanced. Whilst these active processes may contribute to a reduction in blood flow under resting conditions or with mild elevations in metabolic demand, an evolving structural alteration to individual microvessels (reduced distensibility) and microvascular networks (reduced microvessel density) also develop and may act to constrain Perfusion at higher levels of metabolic demand. Given that constrained Muscle Perfusion in the metabolic syndrome appears to reflect a highly integrated, multi-faceted effect in OZR, and probably in humans as well, therapeutic interventions must be designed to address each of these contributing elements.
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impaired skeletal Muscle Perfusion in obese zucker rats
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2003Co-Authors: Jefferson C FrisbeeAbstract:Skeletal Muscle arterioles from obese Zucker rats (OZR) exhibit oxidant stress-based alterations in reactivity, enhanced α-adrenergic constriction, and reduced distensibility vs. microvessels of le...
Martin Krix - One of the best experts on this subject based on the ideXlab platform.
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Comparison of transient arterial occlusion and Muscle exercise provocation for assessment of Perfusion reserve in skeletal Muscle with real-time contrast-enhanced ultrasound
European Journal of Radiology, 2011Co-Authors: Martin Krix, Holger Krakowski-roosen, Erick Armarteifio, Susanne Fürstenberger, Stefan Delorme, Hans-ulrich Kauczor, Marc-andré WeberAbstract:Abstract Objective Contrast-enhanced ultrasound (CEUS) is able to quantify Muscle Perfusion and changes in Perfusion due to Muscle exercise in real-time. However, reliable measurement of standardized Muscle exercise is difficult to perform in clinical examinations. We compared Perfusion reserve assessed by CEUS after transient arterial occlusion and exercise to find the most suitable measurement for clinical application. Methods Contrast pulse sequencing (7 MHz) during continuous IV infusion of SonoVue® (4.8 mL/300 s) was used in 8 healthy volunteers to monitor Muscle Perfusion of the gastrocnemius Muscle during transient (1 min) arterial occlusion produced by a thigh cuff of a venous occlusion plethysmograph. Isometric Muscle exercise (50% of individual maximum strength for 20 s) was subsequently performed during the same examination, and several CEUS parameters obtained from ultrasound-signal-intensity–time curves and its calculation errors were compared. Results The mean maximum local blood volume after occlusion was 13.9 [∼mL] (range, 4.5–28.8 [∼mL]), and similar values were measured after sub-maximum exercise 13.8 [∼mL], (range, 4.6–22.2 [∼mL]. The areas under the curve during rePerfusion vs. recovery were also similar (515.2 ± 257.5 compared to 482.2 ± 187.5 [∼mL s]) with a strong correlation (r = 0.65), as were the times to maximum (15.3 s vs. 15.9 s), with a significantly smaller variation for the occlusion method (±2.1 s vs. ±9.0 s, p = 0.03). The mean errors for all calculated CEUS parameters were lower for the occlusion method than for the exercise test. Conclusions CEUS Muscle Perfusion measurements can be easily performed after transient arterial occlusion. It delivers data which are comparable to CEUS measurements after Muscle exercise but with a higher robustness. This method can be easily applied in clinical examination of patients with e.g. PAOD or diabetic microvessel diseases to assess Perfusion reserve.
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real time contrast enhanced ultrasound for the assessment of Perfusion dynamics in skeletal Muscle
Ultrasound in Medicine and Biology, 2009Co-Authors: Martin Krix, Marc-andré Weber, Stefan Delorme, Hans-ulrich Kauczor, Holger KrakowskiroosenAbstract:We developed a real-time low-MI contrast-enhanced ultrasound method (CEUS), compared it with venous occlusion plethysmography (VOP) and evaluated its robustness in the quantification of skeletal Muscle Perfusion during exercise. Contrast pulse sequencing (7 MHz) during continuous intravenous infusion of SonoVue (4.8 mL/300 s) was used repeatedly in eight healthy volunteers to monitor changes of the Muscle Perfusion before, during and after isometric exercises (10 to 50% of individual maximum strength for 20 to 30 s) of the gastrocnemius Muscle in real time. CEUS was correlated with VOP at different time points, and the exactness of several CEUS parameters obtained from ultrasound-signal-intensity-time curves was evaluated. Real-time CEUS depicted a large variability of the skeletal Muscle blood volume at rest (mean, 3.48; range, 0.60 to 9.92 [approximately mL]), with a significant reproducibility (r=0.72, p<0.05) and correlation with VOP (r=0.59, p<0.001). Mean blood volume during exercise was 1.58(approximately mL), increased to a mean maximum after exercise of 8.88 (approximately mL), the mean change of the local blood volume during and directly after the exercise was -0.10 and +1.57(approximately mL/s). The average CEUS signal during exercise decreased (mean area under the curve, -50.4 [approximately mL.s]) and subsequently increased post exercise (mean 118.6 [approximately mL.s]). CEUS parameters could be calculated with mean relative errors between 6 and 36%. Continuous assessment of local Muscle microcirculation during exercise is possible with real-time CEUS with an acceptable robustness. Its application may be of particular interest in a better understanding of the role of Perfusion during Muscle training, and the monitoring of pathological vascular response, such as in diabetic microvessel diseases.
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quantitative evaluation of Muscle Perfusion with ceus and with mr
European Radiology, 2007Co-Authors: Marc-andré Weber, Martin Krix, Stefan DelormeAbstract:Functional imaging might increase the role of imaging in muscular diseases, since alterations of Muscle morphology alone are not specific for a particular disease. Perfusion, i.e., the blood flow per tissue and time unit including capillary flow, is an important functional parameter. Pathological changes of skeletal Muscle Perfusion can be found in various clinical conditions, such as degenerative or inflammatory myopathies or peripheral arterial occlusive disease. This article reviews the theoretical basics of functional radiological techniques for assessing skeletal Muscle Perfusion and focuses on contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI) techniques. Also, the applications of microvascular imaging, such as in detection of myositis and for discriminating myositis from other myopathies or evaluating peripheral arterial occlusive disease, are presented, and possible clinical indications are discussed. In conclusion, dedicated MR and CEUS methods are now available that visualize and quantify (patho-)physiologic information about microcirculation within skeletal Muscles in vivo and hence establish a useful diagnostic tool for muscular diseases.
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relationship of skeletal Muscle Perfusion measured by contrast enhanced ultrasonography to histologic microvascular density
Journal of Ultrasound in Medicine, 2006Co-Authors: Marc-andré Weber, Martin Krix, Stefan Delorme, Hans-ulrich Kauczor, Holger Krakowskiroosen, Hanna Renk, Juan Millies, Ralf Kinscherf, Annette Kunkele, Wulf HildebrandtAbstract:OBJECTIVE The purpose of this study was to compare skeletal Muscle Perfusion measured by contrast-enhanced ultrasonography (CEUS) with microvascular density in Muscle biopsies. METHODS Power Doppler sonography after intravenous bolus injection of Levovist (SH U 508A; Schering AG, Berlin, Germany) was used to examine Perfusion of vastus lateralis Muscle in 23 healthy volunteers. Local blood volume (B), blood flow velocity (v), and blood flow (f) were calculated by analyzing replenishment kinetics. CEUS Perfusion was compared with vascularization of biopsy samples from vastus lateralis Muscle. Subjects were selected such that their aerobic capacity (maximal oxygen uptake [VO(2)max]) per body weight ranged between 23 and 66 mL . min(-1) . kg(-1) to render a large variability of skeletal Muscle capillarization. Moreover, subjects' venous blood hematocrit (Hkt) was determined to estimate the plasmatic intravascular volume fraction (1-Hkt=PVF) in which the microbubbles can distribute. RESULTS Median capillary density was 331/mm(2) (range, 207-469/mm(2)), and median capillary fiber contacts (CFC) were 3.6 (range, 2.3-6.5). CFC was correlated with VO(2)max (r=0.59; P<.01). Among CEUS parameters, B showed the closest correlation to CFC (r=0.53; P<.01). When CFC was normalized for PVF, correlation of B to CFC was r=0.64 (P<.01). CEUS could depict the physiologic large variability of vastus lateralis Muscle Perfusion at rest (median [range]: B, 2.5 [0.1-12.3] approximately mL; v, 0.3 [0.1-3.7] mm/s; f, 0.7 [0.1-5.3] approximately mL . min(-1) . 100 g tissue(-1)). CONCLUSIONS B is significantly related to fiber-adjacent capillarization and may represent physiologic capillary recruitment (eg, through metabolic fiber-related signals). CEUS is feasible for skeletal Muscle Perfusion quantification.
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pathologic skeletal Muscle Perfusion in patients with myositis detection with quantitative contrast enhanced us initial results
Radiology, 2006Co-Authors: Marc-andré Weber, Martin Krix, Hans-ulrich Kauczor, Hagen B Huttner, Uta Jappe, M Hartmann, Uta Meydinglamade, Marco Essig, Christoph Fiehn, Stefan DelormeAbstract:Purpose: To prospectively determine whether contrast material–enhanced ultrasonography (US) can depict inflammation-induced changes in Muscle Perfusion for patients suspected of having dermatomyositis or polymyositis and to compare these findings with those of magnetic resonance (MR) imaging and Muscle biopsy. Materials and Methods: Institutional review board approval and informed consent were obtained. Perfusion in skeletal Muscles was quantified with contrast-enhanced intermittent power Doppler US by applying a modified model that analyzed the replenishment kinetics of microbubbles. In 22 patients (16 women, six men; mean age, 52 years ± 17) who were suspected of having myositis and in 10 healthy volunteers (two women, eight men; mean age, 28 years ± 4), contrast-enhanced US of the clinically affected right biceps Muscle was performed to measure blood flow, blood volume, and blood flow velocity. Additionally, the right upper arm was examined with a 1.5-T unit by using three different MR imaging techniqu...
Stefan Delorme - One of the best experts on this subject based on the ideXlab platform.
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Comparison of transient arterial occlusion and Muscle exercise provocation for assessment of Perfusion reserve in skeletal Muscle with real-time contrast-enhanced ultrasound
European Journal of Radiology, 2011Co-Authors: Martin Krix, Holger Krakowski-roosen, Erick Armarteifio, Susanne Fürstenberger, Stefan Delorme, Hans-ulrich Kauczor, Marc-andré WeberAbstract:Abstract Objective Contrast-enhanced ultrasound (CEUS) is able to quantify Muscle Perfusion and changes in Perfusion due to Muscle exercise in real-time. However, reliable measurement of standardized Muscle exercise is difficult to perform in clinical examinations. We compared Perfusion reserve assessed by CEUS after transient arterial occlusion and exercise to find the most suitable measurement for clinical application. Methods Contrast pulse sequencing (7 MHz) during continuous IV infusion of SonoVue® (4.8 mL/300 s) was used in 8 healthy volunteers to monitor Muscle Perfusion of the gastrocnemius Muscle during transient (1 min) arterial occlusion produced by a thigh cuff of a venous occlusion plethysmograph. Isometric Muscle exercise (50% of individual maximum strength for 20 s) was subsequently performed during the same examination, and several CEUS parameters obtained from ultrasound-signal-intensity–time curves and its calculation errors were compared. Results The mean maximum local blood volume after occlusion was 13.9 [∼mL] (range, 4.5–28.8 [∼mL]), and similar values were measured after sub-maximum exercise 13.8 [∼mL], (range, 4.6–22.2 [∼mL]. The areas under the curve during rePerfusion vs. recovery were also similar (515.2 ± 257.5 compared to 482.2 ± 187.5 [∼mL s]) with a strong correlation (r = 0.65), as were the times to maximum (15.3 s vs. 15.9 s), with a significantly smaller variation for the occlusion method (±2.1 s vs. ±9.0 s, p = 0.03). The mean errors for all calculated CEUS parameters were lower for the occlusion method than for the exercise test. Conclusions CEUS Muscle Perfusion measurements can be easily performed after transient arterial occlusion. It delivers data which are comparable to CEUS measurements after Muscle exercise but with a higher robustness. This method can be easily applied in clinical examination of patients with e.g. PAOD or diabetic microvessel diseases to assess Perfusion reserve.
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real time contrast enhanced ultrasound for the assessment of Perfusion dynamics in skeletal Muscle
Ultrasound in Medicine and Biology, 2009Co-Authors: Martin Krix, Marc-andré Weber, Stefan Delorme, Hans-ulrich Kauczor, Holger KrakowskiroosenAbstract:We developed a real-time low-MI contrast-enhanced ultrasound method (CEUS), compared it with venous occlusion plethysmography (VOP) and evaluated its robustness in the quantification of skeletal Muscle Perfusion during exercise. Contrast pulse sequencing (7 MHz) during continuous intravenous infusion of SonoVue (4.8 mL/300 s) was used repeatedly in eight healthy volunteers to monitor changes of the Muscle Perfusion before, during and after isometric exercises (10 to 50% of individual maximum strength for 20 to 30 s) of the gastrocnemius Muscle in real time. CEUS was correlated with VOP at different time points, and the exactness of several CEUS parameters obtained from ultrasound-signal-intensity-time curves was evaluated. Real-time CEUS depicted a large variability of the skeletal Muscle blood volume at rest (mean, 3.48; range, 0.60 to 9.92 [approximately mL]), with a significant reproducibility (r=0.72, p<0.05) and correlation with VOP (r=0.59, p<0.001). Mean blood volume during exercise was 1.58(approximately mL), increased to a mean maximum after exercise of 8.88 (approximately mL), the mean change of the local blood volume during and directly after the exercise was -0.10 and +1.57(approximately mL/s). The average CEUS signal during exercise decreased (mean area under the curve, -50.4 [approximately mL.s]) and subsequently increased post exercise (mean 118.6 [approximately mL.s]). CEUS parameters could be calculated with mean relative errors between 6 and 36%. Continuous assessment of local Muscle microcirculation during exercise is possible with real-time CEUS with an acceptable robustness. Its application may be of particular interest in a better understanding of the role of Perfusion during Muscle training, and the monitoring of pathological vascular response, such as in diabetic microvessel diseases.
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quantitative evaluation of Muscle Perfusion with ceus and with mr
European Radiology, 2007Co-Authors: Marc-andré Weber, Martin Krix, Stefan DelormeAbstract:Functional imaging might increase the role of imaging in muscular diseases, since alterations of Muscle morphology alone are not specific for a particular disease. Perfusion, i.e., the blood flow per tissue and time unit including capillary flow, is an important functional parameter. Pathological changes of skeletal Muscle Perfusion can be found in various clinical conditions, such as degenerative or inflammatory myopathies or peripheral arterial occlusive disease. This article reviews the theoretical basics of functional radiological techniques for assessing skeletal Muscle Perfusion and focuses on contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI) techniques. Also, the applications of microvascular imaging, such as in detection of myositis and for discriminating myositis from other myopathies or evaluating peripheral arterial occlusive disease, are presented, and possible clinical indications are discussed. In conclusion, dedicated MR and CEUS methods are now available that visualize and quantify (patho-)physiologic information about microcirculation within skeletal Muscles in vivo and hence establish a useful diagnostic tool for muscular diseases.
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relationship of skeletal Muscle Perfusion measured by contrast enhanced ultrasonography to histologic microvascular density
Journal of Ultrasound in Medicine, 2006Co-Authors: Marc-andré Weber, Martin Krix, Stefan Delorme, Hans-ulrich Kauczor, Holger Krakowskiroosen, Hanna Renk, Juan Millies, Ralf Kinscherf, Annette Kunkele, Wulf HildebrandtAbstract:OBJECTIVE The purpose of this study was to compare skeletal Muscle Perfusion measured by contrast-enhanced ultrasonography (CEUS) with microvascular density in Muscle biopsies. METHODS Power Doppler sonography after intravenous bolus injection of Levovist (SH U 508A; Schering AG, Berlin, Germany) was used to examine Perfusion of vastus lateralis Muscle in 23 healthy volunteers. Local blood volume (B), blood flow velocity (v), and blood flow (f) were calculated by analyzing replenishment kinetics. CEUS Perfusion was compared with vascularization of biopsy samples from vastus lateralis Muscle. Subjects were selected such that their aerobic capacity (maximal oxygen uptake [VO(2)max]) per body weight ranged between 23 and 66 mL . min(-1) . kg(-1) to render a large variability of skeletal Muscle capillarization. Moreover, subjects' venous blood hematocrit (Hkt) was determined to estimate the plasmatic intravascular volume fraction (1-Hkt=PVF) in which the microbubbles can distribute. RESULTS Median capillary density was 331/mm(2) (range, 207-469/mm(2)), and median capillary fiber contacts (CFC) were 3.6 (range, 2.3-6.5). CFC was correlated with VO(2)max (r=0.59; P<.01). Among CEUS parameters, B showed the closest correlation to CFC (r=0.53; P<.01). When CFC was normalized for PVF, correlation of B to CFC was r=0.64 (P<.01). CEUS could depict the physiologic large variability of vastus lateralis Muscle Perfusion at rest (median [range]: B, 2.5 [0.1-12.3] approximately mL; v, 0.3 [0.1-3.7] mm/s; f, 0.7 [0.1-5.3] approximately mL . min(-1) . 100 g tissue(-1)). CONCLUSIONS B is significantly related to fiber-adjacent capillarization and may represent physiologic capillary recruitment (eg, through metabolic fiber-related signals). CEUS is feasible for skeletal Muscle Perfusion quantification.
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pathologic skeletal Muscle Perfusion in patients with myositis detection with quantitative contrast enhanced us initial results
Radiology, 2006Co-Authors: Marc-andré Weber, Martin Krix, Hans-ulrich Kauczor, Hagen B Huttner, Uta Jappe, M Hartmann, Uta Meydinglamade, Marco Essig, Christoph Fiehn, Stefan DelormeAbstract:Purpose: To prospectively determine whether contrast material–enhanced ultrasonography (US) can depict inflammation-induced changes in Muscle Perfusion for patients suspected of having dermatomyositis or polymyositis and to compare these findings with those of magnetic resonance (MR) imaging and Muscle biopsy. Materials and Methods: Institutional review board approval and informed consent were obtained. Perfusion in skeletal Muscles was quantified with contrast-enhanced intermittent power Doppler US by applying a modified model that analyzed the replenishment kinetics of microbubbles. In 22 patients (16 women, six men; mean age, 52 years ± 17) who were suspected of having myositis and in 10 healthy volunteers (two women, eight men; mean age, 28 years ± 4), contrast-enhanced US of the clinically affected right biceps Muscle was performed to measure blood flow, blood volume, and blood flow velocity. Additionally, the right upper arm was examined with a 1.5-T unit by using three different MR imaging techniqu...
Jonathan R Lindner - One of the best experts on this subject based on the ideXlab platform.
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quantification of residual limb skeletal Muscle Perfusion with contrast enhanced ultrasound during application of a focal junctional tourniquet
Journal of Vascular Surgery, 2016Co-Authors: Brian P Davidson, Todd J Belcik, Brian Mott, Gregory J Landry, Jonathan R LindnerAbstract:Objective Focal junctional tourniquets (JTs) have been developed to control hemorrhage from proximal limb injuries. These devices may permit greater collateral Perfusion than circumferential tourniquets. We hypothesized that JTs eliminate large-vessel pulse pressure yet allow a small amount of residual limb Perfusion that could be useful for maintaining tissue viability. Methods Ten healthy control subjects were studied. Transthoracic echocardiography, Doppler ultrasound of the femoral artery (FA) and posterior tibial artery, and contrast-enhanced ultrasound (CEU) Perfusion imaging of the anterior thigh extensor and calf plantar flexor Muscles were performed at baseline and during application of a JT over the common FA. Intramuscular arterial pulsatility index was also measured from CEU intensity variation during the cardiac cycle. Results FA flow was eliminated by JTs in all subjects; posterior tibial flow was eliminated in all but one. Perfusion measured in the thigh and calf Muscles was similar at baseline (0.33 ± 0.29 vs 0.29 ± 0.22 mL/min/g). Application of the JT resulted in a reduction of Perfusion ( P Conclusions Application of a JT eliminates conduit arterial pulse and markedly reduces intramuscular pulse pressure, but thigh and calf skeletal Muscle Perfusion is maintained at 25% to 35% of basal levels. These data suggest that JTs that are used to control limb hemorrhage allow residual tissue Perfusion even when pulse pressure is absent.
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contrast enhanced ultrasound assessment of impaired adipose tissue and Muscle Perfusion in insulin resistant mice
Circulation-cardiovascular Imaging, 2015Co-Authors: Todd J Belcik, Brian P Davidson, Ted Foster, Yan Zhao, Dawn Peters, Jonathan R LindnerAbstract:Background— In diabetes mellitus, reduced Perfusion and capillary surface area in skeletal Muscle, which is a major glucose storage site, contribute to abnormal glucose homeostasis. Using contrast-enhanced ultrasound, we investigated whether abdominal adipose tissue Perfusion is abnormal in insulin resistance and correlates with glycemic control. Methods and Results— Contrast-enhanced ultrasound Perfusion imaging of abdominal adipose tissue and skeletal Muscle was performed in obese insulin resistance (db/db) mice at 11 to 12 or 14 to 16 weeks of age and in control lean mice. Time–intensity data were analyzed to quantify microvascular blood flow (MBF) and capillary blood volume (CBV). Blood glucose response for 1 hour was measured after insulin challenge (1 U/kg, IP). Compared with control mice, db/db mice at 11 to 12 and 14 to 16 weeks had a higher glucose concentration area under the curve after insulin (11.8±2.8, 20.6±4.3, and 28.4±5.9 mg·min/dL [×1000], respectively; P =0.0002) and also had lower adipose MBF (0.094±0.038, 0.035±0.010, and 0.023±0.01 mL/min per gram; P =0.0002) and CBV (1.6±0.6, 1.0±0.3, and 0.5±0.1 mL/100 g; P =0.0017). The glucose area under the curve correlated in a nonlinear fashion with both adipose and skeletal Muscle MBF and CBV. There were significant linear correlations between adipose and Muscle MBF ( r =0.81) and CBV ( r =0.66). Adipocyte cell volume on histology was 25-fold higher in 14- to 16-week db/db versus control mice. Conclusions— Abnormal adipose MBF and CBV in insulin resistance can be detected by contrast-enhanced ultrasound and correlates with the degree of impairment in glucose storage. Abnormalities in adipose tissue and Muscle seem to be coupled. Impaired adipose tissue Perfusion is in part explained by an increase in adipocyte size without proportional vascular response.
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epoxyeicosatrienoic acids mediate insulin mediated augmentation in skeletal Muscle Perfusion and blood volume
American Journal of Physiology-endocrinology and Metabolism, 2014Co-Authors: Chi Young Shim, Brian P Davidson, Sajeevani Kim, Scott M Chadderdon, Aris Xie, Nabil J Alkayed, Jonathan R LindnerAbstract:Skeletal Muscle microvascular blood flow (MBF) increases in response to physiological hyperinsulinemia. This vascular action of insulin may facilitate glucose uptake. We hypothesized that epoxyeico...
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physiologic hyperinsulinemia enhances human skeletal Muscle Perfusion by capillary recruitment
Diabetes, 2001Co-Authors: Matthew Coggins, Jonathan R Lindner, Steve Rattigan, Linda A Jahn, Elizabeth Fasy, Sanjiv Kaul, Eugene J BarrettAbstract:Despite intensive study, the relation between insulin’s action on blood flow and glucose metabolism remains unclear. Insulin-induced changes in microvascular Perfusion, independent from effects on total blood flow, could be an important variable contributing to insulin’s metabolic action. We hypothesized that modest, physiologic increments in plasma insulin concentration alter microvascular Perfusion in human skeletal Muscle and that these changes can be assessed using contrast-enhanced ultrasound (CEU), a validated method for quantifying flow by measurement of microvascular blood volume (MBV) and microvascular flow velocity (MFV). In the first protocol, 10 healthy, fasting adults received insulin (0.05 mU · kg −1 · min −1 ) via a brachial artery for 4 h under euglycemic conditions. At baseline and after insulin infusion, MBV and MFV were measured by CEU during continuous intravenous infusion of albumin microbubbles with intermittent harmonic ultrasound imaging of the forearm deep flexor Muscles. In the second protocol, 17 healthy, fasting adults received a 4-h infusion of either insulin (0.1 mU · kg −1 · min −1 , n = 9) or saline ( n = 8) via a brachial artery. Microvascular volume was assessed in these subjects by an alternate CEU technique using an intra-arterial bolus injection of albumin microbubbles at baseline and after the 4-h infusion. With both protocols, Muscle glucose uptake, plasma insulin concentration, and total blood flow to the forearm were measured at each stage. In protocol 2 subjects, tissue extraction of 1-methylxanthine (1-MX) was measured as an index of perfused capillary volume. Caffeine, which produces 1-MX as a metabolite, was administered to these subjects before the study to raise plasma 1-MX levels. In protocol 1 subjects, insulin increased Muscle glucose uptake (180%, P P P = 0.07) in the absence of significant changes in total forearm blood flow. In protocol 2 subjects, insulin increased glucose uptake (220%, P P P
