Method and apparatus to produce ultrasonic images using multiple apertures

• US 8,684,936 B2
• Filed: 10/01/2012
• Issued: 04/01/2014
• Est. Priority Date: 10/25/2006
• Status: Active Grant

• Current Assignee: Maui Imaging, Inc.
• Original Assignee: Maui Imaging, Inc.
• Inventors: Specht, Donald F.
• Primary Examiner(s): Cattungal, Sanjay
• Application Number:
  US13/632,929
• Publication Number:
  US 20130035595A1
• Time in Patent Office: 547 Days
• Field of Search: 600437-469, 382128-132
• US Class Current: 600/459
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/085 for locating body or organic structures, e.g. tumours, calculi, blood vessels, nodules
• CPC Class Codes: A61B 8/145 characterised by scanning multiple planes
• CPC Class Codes: A61B 8/42 Details of probe positioning or probe attachment to the patient
• CPC Class Codes: A61B 8/4209 by using holders, e.g. positioning frames
• CPC Class Codes: A61B 8/4218 characterised by articulated arms
• CPC Class Codes: A61B 8/4245 involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 8/4455 Features of the external shape of the probe, e.g. ergonomic aspects
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: A61B 8/4494 characterised by the arrangement of the transducer elements devices for short-range imaging using particular transducer elements arrangements under G01S15/8909; arrangements of transducers in generation of mechanical vibrations of infrasonic, sonic or ultrasonic frequency B06B1/0607
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 8/5207 involving processing of raw data to produce diagnostic data, e.g. for generating an image reconstruction G06T11/00
• CPC Class Codes: A61B 8/5253 combining overlapping images, e.g. spatial compounding
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: G01S 15/8977 using special techniques for image reconstruction, e.g. FFT, geometrical transformations, spatial deconvolution, time deconvolution
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00
• CPC Class Codes: G01S 7/5205 Means for monitoring or calibrating

Abstract

A combination of an ultrasonic scanner and an omnidirectional receive transducer for producing a two-dimensional image from received echoes is described. Two-dimensional images with different noise components can be constructed from the echoes received by additional transducers. These can be combined to produce images with better signal to noise ratios and lateral resolution. Also disclosed is a method based on information content to compensate for the different delays for different paths through intervening tissue is described. The disclosed techniques have broad application in medical imaging but are ideally suited to multi-aperture cardiac imaging using two or more intercostal spaces. Since lateral resolution is determined primarily by the aperture defined by the end elements, it is not necessary to fill the entire aperture with equally spaced elements. Multiple slices using these methods can be combined to form three-dimensional images.

Claims

1. An ultrasound imaging method, comprising:

transmitting a first ultrasound pulse along a first scan line from a transmit transducer array positioned in a first acoustic window relative to a target object to be imaged;

receiving echoes of the transmit pulse with a first omnidirectional receive transducer positioned in a second acoustic window, wherein the second acoustic window does not overlap the first acoustic window;

storing the received echoes in a first line of computer memory;

obtaining transducer position information defining a position and orientation of the transmit transducer array relative to the first omnidirectional receive transducer;

retrieving the stored echoes from the first line of computer memory; and

constructing a first image of the target object along the first scan line from the retrieved echoes and the transducer position information.

2. The method of claim 1, further comprising:

completing a sector scan of the target object by transmitting a plurality of successive ultrasound pulses along a plurality of successive scan lines from the transmit transducer array;

receiving echoes of each of the plurality of successive ultrasound pulses with the first omnidirectional receive transducer; and

storing the received echoes from each of the plurality of successive ultrasound pulses in a plurality of successive lines of computer memory.

3. The method of claim 2, further comprising:

retrieving the stored echoes from each of the plurality of successive lines of computer memory;

constructing a plurality of images of the target object along each of the plurality of successive scan lines from the received echoes and the transducer position information; and

combining the first image and the plurality of images along each of the plurality of successive scan lines to form a 2D image.

4. The method of claim 3, further comprising:

receiving echoes of the transmit pulses with a second omnidirectional receive transducer positioned in a third acoustic window; and

storing the echoes received by the second omnidirectional receive transducer in the successive lines of computer memory.

5. The method of claim 4, further comprising:

retrieving the stored echoes received by the second omnidirectional receive transducer from the successive lines of computer memory;

obtaining secondary transducer position information defining a position and orientation of the transmit transducer array relative to the second omnidirectional receive transducer;

constructing a second image of the target object along the plurality of successive scan lines from the received echoes and the secondary transducer position information; and

combining the first and second images to form a combined image.

6. The method of claim 5, further comprising, prior to combining the first and second images, adjusting at least one of the first and second images by correcting for displacement in horizontal and vertical positions.

7. The method of claim 6, further comprising applying cross-correlation techniques to correct for the displacement in horizontal and vertical positions.

8. The method of claim 4, wherein at least one of the first and second omnidirectional receive transducers comprises a single transducer element of a larger array.

9. The method of claim 4, wherein at least one of the first and second omnidirectional receive transducers comprises a group of transducer elements of a larger array.

10. The method of claim 1, wherein the target object is human tissue.

11. The method of claim 10, wherein the target object is a human heart.

12. The method of claim 11, wherein the first acoustic window is selected from the group consisting of a first parasternal intercostal space, a second parasternal intercostal space, a suprasternal notch, a substernal position, a subcostal window, an apical view, a first intercostal space adjacent the sternum, and a second intercostal space adjacent the sternum, and wherein the second acoustic window is selected from the same group.

13. The method of claim 1, further comprising plotting additional scan lines that were not explicitly insonified by the transmit transducer array.

14. The method of claim 4 wherein the second omnidirectional receive transducer comprises at least one transducer element from the transmit transducer array.

15. The method of claim 4, wherein the second omnidirectional receive transducer comprises a third transducer that is separate from the transmit transducer array and the first omnidirectional receive transducer.