Magnetic resonance measurement of velocity and flow: Technique, validation, and cardiovascular applications

Rebergen, Sidney A.; Wall, Ernst E. van der; Doornbos, Joost; Roos, Albert de

doi:10.1016/0002-8703(93)90544-j

Cited by 181 publications

(83 citation statements)

References 99 publications

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“…This problem can partly be resolved by substitution of total with forward SV determined by aortic flow measurements derived by echocardiography 27 or magnetic resonance imaging. 28 The subsequent calculation of the so-called forward SW, however, may not accurately reflect actual SW in these patients. Mitral regurgitation, therefore, remains an important source of error in noninvasive quantification of EW.…”

Section: Circulation February 20 2007mentioning

confidence: 99%

Myocardial Energetics and Efficiency

et al. 2007

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T he heart is an aerobic organ that relies almost exclusively on the aerobic oxidation of substrates for generation of energy. Consequently, there is close coupling between myocardial oxygen consumption (MV O 2 ) and the main determinants of systolic function: heart rate, contractile state, and wall stress. 1 As in any mechanical pump, only part of the energy invested is converted to external power. In the case of the heart, the ratio of useful energy produced (ie, stroke work [SW]) to oxygen consumed is defined as mechanical efficiency, as originally proposed by Bing et al. 2 Under normal conditions this ratio is Ϸ25%, and the residual energy mainly dissipates as heat. 3 In pathophysiological disease states, such as heart failure, mechanical efficiency is reduced, and it has been hypothesized that the increased energy expenditure relative to work contributes to progression of the disease. 4,5 Moreover, therapeutic interventions that enhance mechanical efficiency have proven to be beneficial with respect to outcome. 6 It is therefore desirable to quantify efficiency of the heart to study disease processes and monitor interventions.Both cardiac oxidative metabolism and mechanical work, and thus efficiency, can be quantified through invasive measurements. Although these measurements are accurate and currently considered the gold standard, in clinical practice they are limited because of the need for dual-sided heart catheterization and selective catheterization of the coronary sinus. Recent advances in imaging techniques, however, offer the possibility to noninvasively estimate MV O 2 and mechanical work by positron emission tomography and echocardiography or by magnetic resonance imaging, respectively. This review discusses the principles of mechanical efficiency, together with its invasive and noninvasive assessment, as well as their strengths and pitfalls. Finally, results from clinical pathophysiological studies are discussed. Invasive Measurement of Mechanical EfficiencyTo calculate the efficiency of the heart, input and output energy must be obtained. The first can be derived from MV O 2 (mL O2 · min Ϫ1 ) measurements according to the Fickprinciple by multiplying coronary sinus blood flow (mL · min Ϫ1 ) by the arteriovenous oxygen content difference. 7Blood flow can be estimated with the use of thermodilution or Doppler (electromagnetic flowmeter) methods after accessing the coronary sinus through right-sided heart catheterization. As oxygen dissolved in blood is negligible and hemoglobin concentrations in arterial and venous blood are similar, arteriovenous oxygen content difference can be obtained by determination of the differences in oxygen saturation levels between arterial and coronary sinus blood. This method to determine oxygen utilization is currently considered the gold standard, although it should be noted that it is limited by its invasive nature, susceptibility to sampling errors, and the fact that only global MV O 2 can be assessed, which also includes oxidative metabolism of the right ventricl...

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Section: Circulation February 20 2007mentioning

confidence: 99%

Myocardial Energetics and Efficiency

et al. 2007

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“…20 Velocity maps were acquired with a flip angle of 30°, an echo time of 10 to 12 ms, a section thickness of 8 mm, a field of view of 350 mm, and two measurements of a 128ϫ128 pixel acquisition matrix. The number of time frames varied according to heart rate, resulting in a temporal resolution of 25 to 30 ms.…”

Section: Flow-velocity Measurementsmentioning

confidence: 99%

Functional and Metabolic Evaluation of the Athlete’s Heart By Magnetic Resonance Imaging and Dobutamine Stress Magnetic Resonance Spectroscopy

et al. 1998

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Background-The question of whether training-induced left ventricular hypertrophy in athletes is a physiological rather than a pathophysiological phenomenon remains unresolved. The purpose of the present study was to detect any abnormalities in cardiac function in hypertrophic hearts of elite cyclists and to examine the response of myocardial high-energy phosphate metabolism to high workloads induced by atropine-dobutamine stress. Methods and Results-We studied 21 elite cyclists and 12 healthy control subjects. Left ventricular mass, volume, and function were determined by cine MRI. Myocardial high-energy phosphates were examined by 31 P magnetic resonance spectroscopy. There were no significant differences between cyclists and control subjects for left ventricular ejection fraction (59Ϯ5% versus 61Ϯ4%), left ventricular cardiac index (3.4Ϯ0.4 versus 3.4Ϯ0.4 L ⅐ min Ϫ1 ⅐ m Ϫ2 ), peak early filling rate (562Ϯ93 versus 535Ϯ81 mL/s), peak atrial filling rate (315Ϯ93 versus 333Ϯ65 mL/s), ratio of early and atrial filling volumes (3.0Ϯ1.0 versus 2.6Ϯ0.6), mean acceleration gradient of early filling (5.2Ϯ1.4 versus 5.8Ϯ1.9 L/s 2 ), mean deceleration gradient of early filling(Ϫ3.1Ϯ0.9 versus Ϫ3.2Ϯ0.7 L/s

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“…Phase contrast magnetic resonance imaging (PC-MRI) is a technique which has been extensively used at 1.5 Tesla to determine blood velocity or flow within vessels such as the aorta, carotid arteries, and renal arteries (Bakker et al, 1995;Chatzimavroudis et al, 2001;Evans et al, 1993;Hoogeveen et al, 1998;Pelc et al, 1991;Rebergen et al, 1993). Few studies, however, have used PC-MRI to measure coronary flow due to; 1) the large degree of cardiac motion of the vessels, 2) the large amount and respiratory motion of the vessels, and 3) the small diameter of the vessels.…”

Section: Introductionmentioning

confidence: 99%

Coronary artery flow measurement using navigator echo gated phase contrast magnetic resonance velocity mapping at 3.0 T

Johnson

Sharma

Oshinski

2008

Journal of Biomechanics

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A validation study and early results for noninvasive, in vivo measurement of coronary artery blood flow using phase contrast magnetic resonance imaging (PC-MRI) at 3.0 Tesla is presented. Accuracy of coronary artery blood flow measurements by phase contrast MRI is limited by heart and respiratory motion as well as the small size of the coronary arteries. In this study, a navigator-echo gated, cine phase velocity mapping technique is described to obtain time-resolved velocity and flow waveforms of small diameter vessels at 3.0 Tesla. Phantom experiments using steady, laminar flow are presented to validate the technique and show flow rates measured by 3.0 Tesla phase contrast MRI to be accurate within 15% of true flow rates. Subsequently, in vivo scans on healthy volunteers yield velocity measurements for blood flow in the right, left anterior descending, and left circumflex arteries. Measurements of average, cross-sectional velocity were obtainable in 224/243 (92%) of the cardiac phases. Time-averaged, cross-sectional velocity of the blood flow was 6.8±4.3 cm/s in the LAD, 8.0 ±3.8 cm/s in the LCX, and 6.0±1.6 cm/s in the RCA.

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Magnetic resonance measurement of velocity and flow: Technique, validation, and cardiovascular applications

Cited by 181 publications

References 99 publications

Myocardial Energetics and Efficiency

Myocardial Energetics and Efficiency

Functional and Metabolic Evaluation of the Athlete’s Heart By Magnetic Resonance Imaging and Dobutamine Stress Magnetic Resonance Spectroscopy

Coronary artery flow measurement using navigator echo gated phase contrast magnetic resonance velocity mapping at 3.0 T

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