The Experts below are selected from a list of 259602 Experts worldwide ranked by ideXlab platform
Vivek Muthurangu - One of the best experts on this subject based on the ideXlab platform.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Background Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity. Wave intensity was derived in terms of area and velocity changes. These data were directly derived from PC-CMR using a breath-hold spiral sequence accelerated with sensitivity encoding (SENSE). Image processing was integrated in a plug-in for the DICOM viewer OsiriX, including calculations of wave speed and wave intensity. Ascending and descending aortic data from 15 healthy volunteers (30 ± 6 years) data were used to test the method for feasibility, and intra- and inter-observer variability. Ascending aortic data were also compared with results from 15 patients with coronary heart disease (61 ± 13 years) to assess the clinical usefulness of the method. Rapid image acquisition (11 s breath-hold) and image processing was feasible in all volunteers. Wave speed was physiological (5.8 ± 1.3 m/s ascending aorta, 5.0 ± 0.7 m/s descending aorta) and the wave intensity pattern was consistent with traditionally formulated wave intensity. Wave speed, peak forward compression wave in early systole and peak forward expansion wave in late systole at both locations exhibited overall good intra- and inter-observer variability. Patients with coronary heart disease had higher wave speed (p <0.0001), and lower forward compression wave (p <0.0001) and forward expansion wave (p <0.0005) peaks. This difference is likely related to the older age of the patients’ cohort, indicating stiffer aortas, as well as compromised ventricular function due to their underlying condition. A non-invasive, semi-automated and reproducible method for performing wave intensity analysis is presented. Its application is facilitated by the use of a very high temporal Resolution spiral sequence. A formulation of wave intensity based on area change has also been proposed, involving no assumptions about the cross-sectional shape of the vessel.
Giovanni Biglino - One of the best experts on this subject based on the ideXlab platform.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Background Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity. Wave intensity was derived in terms of area and velocity changes. These data were directly derived from PC-CMR using a breath-hold spiral sequence accelerated with sensitivity encoding (SENSE). Image processing was integrated in a plug-in for the DICOM viewer OsiriX, including calculations of wave speed and wave intensity. Ascending and descending aortic data from 15 healthy volunteers (30 ± 6 years) data were used to test the method for feasibility, and intra- and inter-observer variability. Ascending aortic data were also compared with results from 15 patients with coronary heart disease (61 ± 13 years) to assess the clinical usefulness of the method. Rapid image acquisition (11 s breath-hold) and image processing was feasible in all volunteers. Wave speed was physiological (5.8 ± 1.3 m/s ascending aorta, 5.0 ± 0.7 m/s descending aorta) and the wave intensity pattern was consistent with traditionally formulated wave intensity. Wave speed, peak forward compression wave in early systole and peak forward expansion wave in late systole at both locations exhibited overall good intra- and inter-observer variability. Patients with coronary heart disease had higher wave speed (p <0.0001), and lower forward compression wave (p <0.0001) and forward expansion wave (p <0.0005) peaks. This difference is likely related to the older age of the patients’ cohort, indicating stiffer aortas, as well as compromised ventricular function due to their underlying condition. A non-invasive, semi-automated and reproducible method for performing wave intensity analysis is presented. Its application is facilitated by the use of a very high temporal Resolution spiral sequence. A formulation of wave intensity based on area change has also been proposed, involving no assumptions about the cross-sectional shape of the vessel.
Robert W Heath - One of the best experts on this subject based on the ideXlab platform.
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falp fast beam alignment in mmwave systems with low Resolution Phase shifters
IEEE Transactions on Communications, 2019Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W HeathAbstract:Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large antenna arrays and hardware constraints. For example, a large amount of training overhead is incurred by exhaustive search-based beam alignment in typical mmWave Phased arrays. In this paper, we present a framework called FALP for Fast beam Alignment with Low-Resolution Phase shifters. FALP uses an efficient set of antenna weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The antenna weight vectors in FALP can be realized in ultra-low power Phase shifters whose Resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in Phased arrays and magnetic resonance imaging.
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falp fast beam alignment in mmwave systems with low Resolution Phase shifters
arXiv: Signal Processing, 2019Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W HeathAbstract:Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large antenna arrays and hardware constraints in these systems. The large amount of training overhead incurred by exhaustive search-based beam alignment in typical mmWave systems is one common example. We present a framework for Fast beam Alignment with Low-Resolution Phase shifters which we refer to as FALP. FALP designs an efficient set of antenna weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The antenna weight vectors in FALP can be realized in ultra-low power Phase shifters whose Resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in Phased arrays and magnetic resonance imaging.
Catriona Baker - One of the best experts on this subject based on the ideXlab platform.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Background Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity. Wave intensity was derived in terms of area and velocity changes. These data were directly derived from PC-CMR using a breath-hold spiral sequence accelerated with sensitivity encoding (SENSE). Image processing was integrated in a plug-in for the DICOM viewer OsiriX, including calculations of wave speed and wave intensity. Ascending and descending aortic data from 15 healthy volunteers (30 ± 6 years) data were used to test the method for feasibility, and intra- and inter-observer variability. Ascending aortic data were also compared with results from 15 patients with coronary heart disease (61 ± 13 years) to assess the clinical usefulness of the method. Rapid image acquisition (11 s breath-hold) and image processing was feasible in all volunteers. Wave speed was physiological (5.8 ± 1.3 m/s ascending aorta, 5.0 ± 0.7 m/s descending aorta) and the wave intensity pattern was consistent with traditionally formulated wave intensity. Wave speed, peak forward compression wave in early systole and peak forward expansion wave in late systole at both locations exhibited overall good intra- and inter-observer variability. Patients with coronary heart disease had higher wave speed (p <0.0001), and lower forward compression wave (p <0.0001) and forward expansion wave (p <0.0005) peaks. This difference is likely related to the older age of the patients’ cohort, indicating stiffer aortas, as well as compromised ventricular function due to their underlying condition. A non-invasive, semi-automated and reproducible method for performing wave intensity analysis is presented. Its application is facilitated by the use of a very high temporal Resolution spiral sequence. A formulation of wave intensity based on area change has also been proposed, involving no assumptions about the cross-sectional shape of the vessel.
Kim H Parker - One of the best experts on this subject based on the ideXlab platform.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Background Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity.
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a non invasive clinical application of wave intensity analysis based on ultrahigh temporal Resolution Phase contrast cardiovascular magnetic resonance
Journal of Cardiovascular Magnetic Resonance, 2012Co-Authors: Giovanni Biglino, Jennifer A Steeden, Catriona Baker, Silvia Schievano, Andrew M Taylor, Kim H Parker, Vivek MuthuranguAbstract:Wave intensity analysis, traditionally derived from pressure and velocity data, can be formulated using velocity and area. Flow-velocity and area can both be derived from high-Resolution Phase-contrast cardiovascular magnetic resonance (PC-CMR). In this study, very high temporal Resolution PC-CMR data is processed using an integrated and semi-automatic technique to derive wave intensity. Wave intensity was derived in terms of area and velocity changes. These data were directly derived from PC-CMR using a breath-hold spiral sequence accelerated with sensitivity encoding (SENSE). Image processing was integrated in a plug-in for the DICOM viewer OsiriX, including calculations of wave speed and wave intensity. Ascending and descending aortic data from 15 healthy volunteers (30 ± 6 years) data were used to test the method for feasibility, and intra- and inter-observer variability. Ascending aortic data were also compared with results from 15 patients with coronary heart disease (61 ± 13 years) to assess the clinical usefulness of the method. Rapid image acquisition (11 s breath-hold) and image processing was feasible in all volunteers. Wave speed was physiological (5.8 ± 1.3 m/s ascending aorta, 5.0 ± 0.7 m/s descending aorta) and the wave intensity pattern was consistent with traditionally formulated wave intensity. Wave speed, peak forward compression wave in early systole and peak forward expansion wave in late systole at both locations exhibited overall good intra- and inter-observer variability. Patients with coronary heart disease had higher wave speed (p <0.0001), and lower forward compression wave (p <0.0001) and forward expansion wave (p <0.0005) peaks. This difference is likely related to the older age of the patients’ cohort, indicating stiffer aortas, as well as compromised ventricular function due to their underlying condition. A non-invasive, semi-automated and reproducible method for performing wave intensity analysis is presented. Its application is facilitated by the use of a very high temporal Resolution spiral sequence. A formulation of wave intensity based on area change has also been proposed, involving no assumptions about the cross-sectional shape of the vessel.
