Method and apparatus to visualize the coronary arteries using ultrasound

• US 8,105,239 B2
• Filed: 09/14/2006
• Issued: 01/31/2012
• Est. Priority Date: 02/06/2006
• Status: Active Grant

• Current Assignee: Maui Imaging, Inc.
• Original Assignee: Maui Imaging, Inc.
• Inventors: Specht, Donald F.
• Primary Examiner(s): Chen, Tse
• Assistant Examiner(s): REMALY, MARK DONALD
• Application Number:
  US11/532,013
• Publication Number:
  US 20070238999A1
• Time in Patent Office: 1,965 Days
• Field of Search: 600407-410, 600/413, 600/420, 600424-426, 600/428, 600/431, 600/436, 600437-450, 600453-458, 358/447, 358/463, 706 1- 8, 706 14- 24, 345/619, 345/642, 345/643, 382155-158, 382/254, 382/260, 382/261
• US Class Current: 600/446
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• 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 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/0883 for diagnosis of the heart
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/4254 using sensors mounted on the probe
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: G06T 2207/10136 3D ultrasound image
• CPC Class Codes: G06T 2207/20092 Interactive image processing based on input by user
• CPC Class Codes: G06T 2207/30048 Heart; Cardiac
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/0012 Biomedical image inspection

Abstract

A non-invasive screening technique for visualizing coronary arteries which overcomes the problems of visualizing the curved arteries by projecting the three dimensional volume of the arteries onto a two dimensional screen. Blood filled areas such as the coronary arteries and veins, are highlighted to contrast with other nearby tissues using non-linear classification and segmentation techniques. Data is gathered as a sequence of 2D slices stored as a 3D volume. Software interpolates voxels intermediate to the slices. Wiener filtering or LMS spatial filtering can be implemented on each 2D scan to improve lateral resolution and reduce noise prior to the use of the scan data with the classification and segmentation algorithms. A traditional handheld ultrasound probe is employed to enable the technician to locate the area of interest, but a gyroscopic stabilizer is added to minimize unwanted variation on two axes of rotation.

Claims

1. A method of reconstructing a 3D image, comprising the steps of:

(a) scanning heart and surrounding tissue with a 2D ultrasound scanner;

(b) recording a succession of 2D scans to image the heart tissue;

(c) filling a plurality of voxels of a 3D array with the recorded 2D scans;

(d) applying an artificial neural network to classify the voxels of the 3D array by selecting voxels representing blood-filled areas of the heart tissue and rejecting voxels representing non blood-filled areas of the surrounding tissue;

(e) discriminating between arteries and veins of the heart tissue and chambers of the heart; and

(f) displaying the arteries and veins of the heart tissue.

2. The method of claim 1, wherein step (a) is performed using a handheld medical ultrasound probe.

3. The method of claim 2, further including the step of stabilizing the medical ultrasound probe with a gyroscopic stabilizer to hold the position of the medical ultrasound probe fixed in pitch and yaw such that it can be rotated with minimal changes in pitch and yaw.

4. The method of claim 3, wherein steps (b) and (c) are performed using a computer, and further including the step of measuring a rotation angle of the medical ultrasound probe with a gyroscope and sending the measurements to the computer.

5. The method of claim 2, further including the step of stabilizing the medical ultrasound probe with a gyroscopic stabilizer to hold the position of the medical ultrasound probe fixed in yaw and roll such that it can be rotated with minimal changes in yaw and roll.

6. The method of claim 5, wherein steps (b) and (c) are performed using a computer, and further including the step of measuring a rotation angle of the medical ultrasound probe with a gyroscope and sending the measurements to the computer.

7. The method of claim 2, further including the step of mounting the handheld medical ultrasound probe in a fixture above the patient and recording a position and angle of each of the succession of recorded scans.

8. The method of claim 2, further including the steps of:

(g) monitoring a position of the handheld medical ultrasound probe; and

(h) sending an electrocardiogram lead to a computer for EKG gating.

9. The method of claim 1, further including the step of using a Wiener Filter to minimize image blur and noise from the succession of scans.

10. The method of claim 1, further including the step of using an adaptive inverse filter to minimize image blur and noise from the succession of scans.

11. The method of claim 1, wherein inputs to the artificial neural network are pixel values from a 2D scan.

12. The method of claim 1, wherein inputs to the artificial neural network are voxel values from a volume array interpolated from the succession of 2D scans.

13. The method of claim 1, further including the step of enhancing segmentation of blood-filled areas by weighting the classification of adjacent pixels or voxels.

14. The method of claim 1, wherein step (e) is accomplished using Classification and Regression Trees.

15. The method of claim 14, further including the step of enhancing segmentation of blood-filled areas by weighting the classification of adjacent pixels or voxels.

16. The method of claim 1, wherein step (e) is accomplished using Hidden Markov Models.

17. The method of claim 16, further including the step of enhancing segmentation of blood-filled areas by weighting the classification of adjacent pixels or voxels.

18. The method of claim 1, wherein step (e) is accomplished using Fuzzy Logic.

19. The method of claim 18, further including the step of enhancing segmentation of blood-filled areas by weighting the classification of adjacent pixels or voxels.

20. The method of claim 1, wherein step (f) includes a 3D image on a screen of only the arteries and veins of the heart tissue.

21. The method of claim 20, further including the step of controlling an angle of view of the 3D image with a computer input device.

22. The method of claim 20, wherein said displaying step displays the 3D image of the arteries and veins of the heart tissue highlighted in intensity or color and superimposed on echos showing the heart and surrounding tissue.

23. The method of claim 22, further including the step of controlling an angle of view of 3D image with a pointing device or other input.