Applications of phase-contrast flow and velocity imaging in cardiovascular MRI

Gatehouse, Peter; Keegan, Jennifer; Crowe, Lindsey A.; Masood, Sharmeen; Mohiaddin, Raad H.; Kreitner, Karl‐Friedrich; Firmin, David N.

doi:10.1007/s00330-005-2829-3

Cited by 288 publications

(208 citation statements)

References 71 publications

(77 reference statements)

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“…11 Variables such as local PWV, arterial distensibility and Young's elastic modulus assess the local intrinsic properties of the arterial wall itself and are more closely related to the biomechanical characteristics of the artery. 12,13 However, because these local variables require cumbersome and/or specialized imaging technologies such as ultrasound imaging systems (that is, echo-wall-tracking) for the peripheral arteries and MRI for the aorta, their use is limited to research laboratories. 5 We recently proposed a simple method for the evaluation of both local and regional AoStiff.…”

Section: Introductionmentioning

confidence: 99%

Assessment of aortic stiffness by local and regional methods

et al. 2011

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The stiffness of large arteries has an important role in cardiovascular hemodynamics. Aortic stiffness (AoStiff) can be assessed non-invasively with regional and local methods. In this paper, we compared these two techniques for evaluating AoStiff. Our subjects comprised of 118 consecutive patients (85 men, mean age: 49 ± 14 years). We evaluated regional AoStiff with carotid-femoral pulse wave velocity (PWV) measured with a tonometric technique and by bioelectrical impedance (BI) wave velocity (IWV). The local AoStiff was calculated from BI signals recorded at the chest. We used glyceryl trinitrate (GTN) to test the effect of peripheral vasodilatation on both methods in a subgroup of 52 patients (37 men, mean age: 52 ± 11 years). We found a significant correlation between IWV and PWV measurements (r¼0.88, Po0.0001) as well as between AoStiff and PWV measurements (r¼0.75, Po0.0001). GTN administration decreased mean arterial blood pressure by 4% (95% confidence interval: 2-8%, P¼0.002) without significant changes in AoStiff and regional IWV. Local AoStiff is correlated with regional measurements and is not influenced by changes in arterial pressure because of systemic peripheral vasodilatation.

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Section: Introductionmentioning

confidence: 99%

Assessment of aortic stiffness by local and regional methods

et al. 2011

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“…To provide a noninvasive estimate of PWV, phase contrast (PC) MRI has been applied in a number of in vivo studies determining blood flow based on flow waveform measurements in single two-dimensional (2D) planes transecting the aorta (8)(9)(10). For PWV estimation, typically transit-time methods are employed estimating temporal differences of specific features of blood flow waveforms, e.g., time from foot to foot or peak to peak, between two locations of the vessel with known distance (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). However, the precision of this method highly depends on the exact calculation of flow difference and distance between only two measuring points (16,25,26).…”

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confidence: 99%

Estimation of global aortic pulse wave velocity by flow‐sensitive 4D MRI

Markl

Wallis

Brendecke

et al. 2010

Magnetic Resonance in Med

114

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The aim of this study was to determine the value of flow-sensitive four-dimensional MRI for the assessment of pulse wave velocity as a measure of vessel compliance in the thoracic aorta. Findings in 12 young healthy volunteers were compared with those in 25 stroke patients with aortic atherosclerosis and an age-matched normal control group (n 5 9). Results from pulse wave velocity calculations incorporated velocity data from the entire aorta and were compared to those of standard methods based on flow waveforms at only two specific anatomic landmarks. Global aortic pulse wave velocity was higher in patients with atherosclerosis (7.03 6 0.24 m/ sec) compared to age-matched controls (6.40 6 0.32 m/sec). Both were significantly (P < 0.001) increased compared to younger volunteers (4.39 6 0.32 m/sec). Global aortic pulse wave velocity in young volunteers was in good agreement with previously reported MRI studies and catheter measurements. Estimation of measurement inaccuracies and error propagation analysis demonstrated only minor uncertainties in measured flow waveforms and moderate relative errors below 16% for aortic compliance in all 46 subjects. These results demonstrate the feasibility of pulse wave velocity calculation based on fourdimensional MRI data by exploiting its full volumetric coverage, which may also be an advantage over standard two-dimensional techniques in the often-distorted route of the aorta in patients with atherosclerosis. Magn Reson Med 63:1575-1582, 2010. V C 2010 Wiley-Liss, Inc. Key words: pulse wave velocity; compliance; phase contrast; atherosclerosis; aorta Increased pulse wave velocity (PWV) as a measure of aortic stiffness is an important marker for both agerelated changes in aortic compliance and the presence of atherosclerosis (1,2) and is an independent predictor of cardiovascular mortality and stroke (3,4). Reliable measurement of PWV is of particular interest for monitoring the progression or regression of vessel compliance during therapy (5,6).Pressure catheter measurements can be considered the gold standard for the assessment of the development of aortic pressure wave, but their use is limited due to the invasiveness of the procedure (7). To provide a noninvasive estimate of PWV, phase contrast (PC) MRI has been applied in a number of in vivo studies determining blood flow based on flow waveform measurements in single two-dimensional (2D) planes transecting the aorta (8-10). For PWV estimation, typically transit-time methods are employed estimating temporal differences of specific features of blood flow waveforms, e.g., time from foot to foot or peak to peak, between two locations of the vessel with known distance (11-24). However, the precision of this method highly depends on the exact calculation of flow difference and distance between only two measuring points (16,25,26).Methodological improvements include a more continuous evaluation along a vessel center line and cross-correlation (XCor) analysis for the estimation of waveform delays, which improved the accuracy of PWV...

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“…Several methods are available for this purpose -phase-contrast sequences quantify anterograde and retrograde flow volumes and velocities in any desired imaging plane, within a vessel or a valvular plane (89,90). The accuracy of phase-contrast measurements as assessed with in vitro models is excellent (91,92) and good correlations have been documented between CMR flow measurements and Doppler echocardiography (93), as well as cardiac catheterization (94,95).…”

Section: Valvular Heart Diseasementioning

confidence: 99%