System and method for ultrasound perfusion imaging

• US 20070167797A1
• Filed: 11/01/2004
• Published: 07/19/2007
• Est. Priority Date: 11/07/2003
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ragter, Patrick, Averkiou, Michalakis
• Granted Patent: US 7,753,850 B2
• Time in Patent Office: Days
• US Class Current: 600/458
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/481 involving the use of contrast agent, e.g. microbubbles introduced into the bloodstream analysis of echo signal exploiting properties of a contrast enhancer in devices for short-range imaging with acoustic waves G01S7/52039
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: G01H 3/00 Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G10K 11/346 using phase variation

Abstract

An ultrasound imaging system transmits a broad beam of ultrasound into tissues that are perfused with blood containing microbubbles. The ultrasound has an intensity that is sufficient to destroy the microbubbles in the tissues. A plurality of ultrasound imaging beams are then transmitted into the tissues over a sufficient period to allow the tissues to re-perfuse, and reflections from the transmitted imaging beams are processed to provide a perfusion image. The transmitted microbubble-destroying ultrasound may be in the form of a single beam or a plurality of beams that insonify a substantially larger area than the area insonified by the transmitted imaging beams. As a result, the microbubbles are all destroyed at substantially the same time, and the imaging ultrasound is transmitted only into regions of the tissues from which ultrasound reflections will be received.

Claims

1. A method of obtaining an ultrasound perfusion image of tissues perfused with blood containing microbubbles, the method comprising:

transmitting a plane wave of microbubble-destroying ultrasound into the tissues, the plane wave of microbubble-destroying ultrasound encompassing a first area of the tissues, the microbubble-destroying ultrasound having an intensity that is sufficient to destroy microbubbles in the tissues that are insonified by the microbubble-destroying ultrasound;

repetitively transmitting a plurality of beams of imaging ultrasound into the tissues, each beam of imaging ultrasound having a second area that is smaller than the first area, the imaging ultrasound having an intensity that is substantially insufficient to destroy microbubbles in the tissues that are insonified by the imaging ultrasound;

receiving reflections from each of the transmitted imaging ultrasound beams in respective receive beams, each of the receive beams having a third area that is smaller than the first area; and

processing the received reflections over a sufficient period to allow re-perfusion of the tissues to provide an ultrasound perfusion image.

4. The method of claim 1 wherein the act of transmitting a plane wave of microbubble-destroying ultrasound into the tissues comprises transmitting a single plane wave of microbubble-destroying ultrasound into the tissues.

7. The method of claim 1 wherein the act of repetitively transmitting a plurality of beams of imaging ultrasound into the tissues and receiving reflections from each of the transmitted imaging ultrasound beams comprises transmitting the beams of imaging ultrasound into the tissues at a first frequency and receiving reflections from the transmitted imaging ultrasound beams at a second frequency that is a harmonic of the first frequency.

8. The method of claim 1 wherein the size of each second area insonified by a respective transmitted imaging beams is substantially equal to the size of the respective third area from which reflections from each of the transmitted imaging ultrasound beams are received.

2. (canceled)

3. A method of obtaining an ultrasound perfusion image of tissues perfused with blood containing microbubbles, the method comprising:

transmitting a broad beam of microbubble-destroying ultrasound into the tissues, the beam of microbubble-destroying ultrasound encompassing a first area of the tissues, the microbubble-destroying ultrasound having an intensity that is sufficient to destroy microbubbles in the tissues that are insonified by the microbubble-destroying ultrasound;

repetitively transmitting a plurality of beams of imaging ultrasound into the tissues, each beam of imaging ultrasound having a second area that is smaller than the first area, the imaging ultrasound having an intensity that is substantially insufficient to destroy microbubbles in the tissues that are insonified by the imaging ultrasound;

receiving reflections from each of the transmitted imaging ultrasound beams in respective receive beams, each of the receive beams having a third area that is smaller than the first area; and

processing the received reflections over a sufficient period to allow re-perfusion of the tissues to provide an ultrasound perfusion image

wherein the act of transmitting a broad beam of microbubble-destroying ultrasound into the tissues comprises sequentially transmitting beams of microbubble-destroying ultrasound at a rate that is sufficiently high that subsequent beams are transmitted before a previously transmitted beam of microbubble-destroying ultrasound has been fully reflected from the tissues.

5. The method of claim 3 wherein the act of transmitting a broad beam of microbubble-destroying ultrasound into the tissues comprises transmitting a sequence of focused beams of microbubble-destroying ultrasound into the tissues.

9. The method of claim 3, wherein transmitting a broad beam of microbubble-destroying ultrasound further comprises setting at least one of the transmission parameters of beam focus, transmit aperture, or transmit apodization in correspondence with a desired first area size.

10. The method of claim 3, wherein transmitting a broad beam of microbubble-destroying ultrasound further comprises transmitting a plurality of broad beams through volumetric regions in different directions.

6. (canceled)

11. A method of obtaining an ultrasound perfusion image of tissues perfused with blood containing microbubbles, the method comprising:

using ultrasound to simultaneously destroy substantially all of the microbubbles in the tissues over a first area; and

repetitively using ultrasound transmitted and received in a plurality of second areas that substantially encompasses the first area to obtain an indication of the quantity of microbubbles in the tissues that are intact over a re-perfusion time, each of the second areas being smaller than the first area,

wherein the act of using ultrasound to simultaneously destroy substantially all of the microbubbles in the tissues over a first area comprises using a plane-wave beam of ultrasound to simultaneously destroy substantially all of the microbubbles in the tissues over the first area.

12. The method of claim 11 wherein the act of using ultrasound to simultaneously destroy substantially all of the microbubbles in the tissues over a first area comprises using a broad beam of ultrasound to simultaneously destroy substantially all of the microbubbles in the tissues over the first area.

13-19. -19. (canceled)