Noninvasive quantitation of blood flow turbulence in patients with aortic valve disease using online digital computer analysis of Doppler velocity data

Isaaz, Karl; Bruntz, J. F.; Costa, Antoine Da; Winninger, Daniel; Cerisier, Alexis; Chillou, Christian de; Sadoul, Nicolas; Lamaud, M; Éthevenot, Gérard; Aliot, Étienne

doi:10.1016/s0894-7317(03)00420-6

Cited by 21 publications

(9 citation statements)

References 43 publications

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“…Invasive hot film/wire anemometry and perivascular Doppler ultrasound have the ability to provide some information on turbulence intensity in vivo (32,33). Noninvasive echocardiography methods have also been proposed and may be able to contribute with first-order estimations of nonlaminar flow effects associated with aortic stenosis (34,35). …”

Section: Discussionmentioning

confidence: 99%

Magnetic Resonance Measurement of Turbulent Kinetic Energy for the Estimation of Irreversible Pressure Loss in Aortic Stenosis

Dyverfeldt

Hope

Tseng

et al. 2013

JACC: Cardiovascular Imaging

134

157

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OBJECTIVES The authors sought to measure the turbulent kinetic energy (TKE) in the ascending aorta of patients with aortic stenosis and to assess its relationship to irreversible pressure loss. BACKGROUND Irreversible pressure loss caused by energy dissipation in post-stenotic flow is an important determinant of the hemodynamic significance of aortic stenosis. The simplified Bernoulli equation used to estimate pressure gradients often misclassifies the ventricular overload caused by aortic stenosis. The current gold standard for estimation of irreversible pressure loss is catheterization, but this method is rarely used due to its invasiveness. Post-stenotic pressure loss is largely caused by dissipation of turbulent kinetic energy into heat. Recent developments in magnetic resonance flow imaging permit noninvasive estimation of TKE. METHODS The study was approved by the local ethics review board and all subjects gave written informed consent. Three-dimensional cine magnetic resonance flow imaging was used to measure TKE in 18 subjects (4 normal volunteers, 14 patients with aortic stenosis with and without dilation). For each subject, the peak total TKE in the ascending aorta was compared with a pressure loss index. The pressure loss index was based on a previously validated theory relating pressure loss to measures obtainable by echocardiography. RESULTS The total TKE did not appear to be related to global flow patterns visualized based on magnetic resonance–measured velocity fields. The TKE was significantly higher in patients with aortic stenosis than in normal volunteers (p < 0.001). The peak total TKE in the ascending aorta was strongly correlated to index pressure loss (R2 = 0.91). CONCLUSIONS Peak total TKE in the ascending aorta correlated strongly with irreversible pressure loss estimated by a well-established method. Direct measurement of TKE by magnetic resonance flow imaging may, with further validation, be used to estimate irreversible pressure loss in aortic stenosis.

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Section: Discussionmentioning

confidence: 99%

Magnetic Resonance Measurement of Turbulent Kinetic Energy for the Estimation of Irreversible Pressure Loss in Aortic Stenosis

Dyverfeldt

Hope

Tseng

et al. 2013

JACC: Cardiovascular Imaging

134

157

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“…Peak systolic flow conditions were simulated with the CFD program FLUENT 6.3.26 (Ansys, Canonsburg, PA) using flow conditions defined by 4D VEC‐MRI, a non‐Newtonian blood (density of 1050 kg/m 3 ) model as described previously , and a k‐ω SST transition turbulence model with low aorta inlet turbulence intensity of 5% that is in the range of values measured by Isaaz et al in patients with normal (nonstenosed) aortic valve. Note that the level of the turbulence intensity does not affect the calculation of the pressure drop .…”

Section: Methodsmentioning

confidence: 99%

MRI‐based computational fluid dynamics for diagnosis and treatment prediction: Clinical validation study in patients with coarctation of aorta

Goubergrits

Riesenkampff

Yevtushenko

et al. 2014

Magnetic Resonance Imaging

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“…TURBULENCE AND VELOCITY FLUCTUATIONS of the blood flow are believed to play a role in hemolysis (1), platelet activation (2), thrombus formation (3), or in the development of atherosclerosis (4, 5). Previous invasive studies have assessed turbulence in vivo based on catheter hot‐film anemometry or perivascular Doppler ultrasound in animals (3, 6, 7) and in humans (8–10). However, these studies were limited due to their complexity and invasiveness.…”

mentioning

confidence: 99%

Assessment of flow instabilities in the healthy aorta using flow‐sensitive MRI

Stalder

Frydrychowicz

Russe

et al. 2011

Magnetic Resonance Imaging

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Purpose: To assess blood flow velocities and spatial distribution of aortic Reynolds numbers in vivo using flowsensitive magnetic resonance imaging (MRI) and probe for flow instabilities along the aorta based on an empirical model for physiological pulsatile blood flow. Materials and Methods:Thirty young healthy volunteers were examined by flow-sensitive MRI at eight imaging planes distributed along the thoracic aorta. Flow, Womersley, Strouhal, Reynolds, and critical Reynolds numbers were calculated and used to assess the presence of flow instabilities. Results:The average peak Reynolds number was higher in the ascending (%4500) and descending aorta (%4200) than in the aortic arch (%3400). According to the calculated critical Reynolds numbers, flow instabilities were prominent in the ascending (14/30 volunteers) and descending aorta (22/30 volunteers) but not in the aortic arch (3/30 volunteers). A significant difference (P < 0.05) in supracritical peak Reynolds numbers was observed between genders. The supracritical Reynolds number, indicating flow instabilities, significantly correlated (P < 0.05) with body weight (r ¼ 0.34), aortic diameter (r ¼ 0.48), and cardiac output (r ¼ 0.53).Conclusion: Flow-sensitive MRI was used to indirectly assess the presence of flow instabilities in vivo. The results in volunteers indicate the presence of flow instabilities in the young healthy aorta with a higher prevalence for men than women.

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Noninvasive quantitation of blood flow turbulence in patients with aortic valve disease using online digital computer analysis of Doppler velocity data

Cited by 21 publications

References 43 publications

Magnetic Resonance Measurement of Turbulent Kinetic Energy for the Estimation of Irreversible Pressure Loss in Aortic Stenosis

Magnetic Resonance Measurement of Turbulent Kinetic Energy for the Estimation of Irreversible Pressure Loss in Aortic Stenosis

MRI‐based computational fluid dynamics for diagnosis and treatment prediction: Clinical validation study in patients with coarctation of aorta

Assessment of flow instabilities in the healthy aorta using flow‐sensitive MRI

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