Ultrasound imaging of cardiac anatomy using doppler analysis

A method, comprising:

• emitting an ultrasound beam onto a blood volume from an array of ultrasound transducers in a catheter placed in a blood pool in an organ by providing driving signals to the array of ultrasound transducers;
• adjusting relative phases of the driving signals provided to the array of ultrasound transducers to focus at least a portion of ultrasound beam onto a plurality of locations within the blood volume and varying a focal length of the ultrasound beam to variably collect blood Doppler shifted signals from different multiple blood volumes, the plurality of locations forming a path in blood between the catheter and a wall surface of the organ;
• characterizing a blood velocity profile over the path;
• receiving, in the array, echo signals reflected in response to the emitted ultrasound beam;
• distinguishing, in the echo signals, based on the blood velocity profile, between (i) first spectral signal components having Doppler shifts characteristic of blood and (ii) second spectral signal components having Doppler shifts characteristic of tissue of the organ;
• filtering out the first spectral signal components from the echo signals;
• and
• displaying an ultrasound image based on the second spectral signal components in the echo signals.

A system, comprising:

• a catheter comprising an array of ultrasound transducers, the array configured to be placed in a blood pool in an organ, to emit an ultrasound beam onto a blood volume and to receive echo signals reflected in response to the ultrasound beam;
• and
• a processor, which is configured to:
• provide driving signals to the array of ultrasound transducers;
• adjust relative phases of the driving signals provided to the array of ultrasound transducers to focus at least a portion of ultrasound beam onto a plurality of locations within the blood volume, the plurality of locations forming a path in blood between the catheter and a wall surface of the organ;
• characterize a blood velocity profile over the path;
• distinguish, in the echo signals, based on the blood velocity profile, between (i) first spectral signal components having Doppler shifts characteristic of blood and (ii) second spectral signal components having Doppler shifts characteristic of tissue of the organ;
• filter out the first spectral signal components from the echo signals;
• and
• display an ultrasound image based on the second spectral signal components in the echo signals.