Ultrafast Doppler imaging of blood flow dynamics in the myocardium.
Imaging intramyocardial vascular flows in real-time could strongly help to achieve better diagnostic of cardiovascular diseases. To date, no standard imaging modality allows describing accurately myocardial blood flow dynamics with good spatial and temporal resolution. We recently introduced a novel ultrasonic Doppler imaging technique based on compounded plane waves transmissions at ultrafast frame rate. The high sensitivity of this ultrafast Doppler technique permits to image the intramyocardial blood flow and its dynamics. A dedicated demodulation-filtering process is implemented to compensate for the large tissue velocity of the myocardium during the cardiac cycle. A signed power Doppler processing provides the discrimination between arterial and venous flows. Experiments were performed in vivo in a large animal open chest model ( N = 5 sheep) using a conventional ultrasonic probe placed at the surface of the heart. Results show the capability of the technique to image intramyocardial vascular flows in normal physiological conditions with good spatial (200 μm) and temporal resolution (10 ms). Flow dynamics over the cardiac cycle were investigated and the imaging method demonstrated a phase opposition of flow waveforms between arterial and venous flows. Finally, ultrafast Doppler combined with tissue motion compensation was found able to reveal vascular flow disruption in ischemic regions during occlusion of the main diagonal coronary artery.
Institut Langevin, ESPCI ParisTech, CNRS UMR7587, INSERM 7633, Université Paris VII, 75005, Paris, France. bruno-felix.osmanski@espci.fr
Bruno-Felix
BF
Osmanski
Mathieu
M
Pernot
Gabriel
G
Montaldo
Alain
A
Bel
Emmanuel
E
Messas
Mickael
M
Tanter
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology*; D015150:Echocardiography, Doppler / Q000379:methods*; D006321:Heart / Q000502:physiology*; D017202:Myocardial Ischemia / Q000503:physiopathology; D012756:Sheep