Method and apparatus for acquiring and fusing ultrasound images with pre-acquired images

• US 20160078623A1
• Filed: 09/15/2015
• Published: 03/17/2016
• Est. Priority Date: 09/16/2014
• Status: Active Grant

• Current Assignee: Esaote SpA
• Original Assignee: Esaote SpA
• Inventors: De Beni, Stefano, D'Onofrio, Sara, Bessi, Lorenzo, Forzoni, Leonardo
• Granted Patent: US 10,043,272 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06T 11/003 Reconstruction from projections, e.g. tomography
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10088 Magnetic resonance imaging [MRI]
• CPC Class Codes: G06T 2207/10136 3D ultrasound image
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 2207/30016 Brain
• CPC Class Codes: G06T 2207/30044 Fetus; Embryo
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/0016 involving temporal comparison
• CPC Class Codes: G06T 7/33 using feature-based methods
• CPC Class Codes: G06T 7/38 Registration of image sequences

Abstract

A method of fusing ultrasound images with pre-acquired images includes acquiring a first 3D ultrasound image in real-time; identifying at least one known reference pattern or object within a pre-acquired 3D image and the 3D ultrasound image; registering the real-time 3D ultrasound image with the pre-acquired 3D image by using the reference pattern or object; fusing the 3D ultrasound images of a sequence of real-time 3D ultrasound images; with the pre-acquired 3D image using data of the co-registration; and displaying fusion tomographic images, each including the corresponding real-time ultrasound image and the pre-acquired image. The registration between real-time 3D ultrasound images and the pre-acquired 3D image is performed continuously in the background by continuing to acquire the real-time 3D ultrasound images and to register them with the pre-acquired 3D images using the reference pattern or patterns or the object or objects.

Claims

1. A method of fusing ultrasound images (1) with pre-acquired images (60), comprising the following steps:

a) acquiring (61) a first 3D ultrasound image in real-time;

b) identifying at least one known reference pattern or object within a pre-acquired 3D image and the first 3D ultrasound image;

c) registering (63) the first 3D ultrasound image acquired in real-time with the pre-acquired 3D image by using the reference pattern or object;

d) fusing (64) 3D ultrasound images of a sequence of first 3D ultrasound images acquired in real-time with the pre-acquired 3D image by using data of a co-registration between said first 3D ultrasound image and the pre-acquired 3D image; and

e) displaying (65) fusion tomographic images, each fusion image comprising the corresponding 3D ultrasound image acquired in real-time and the pre-acquired 3D image,

wherein the co-registration (63) between 3D ultrasound images acquired in real-time and the pre-acquired 3D image is performed in a continuous manner in a background, by continuing to acquire in the background the real-time 3D ultrasound images and to register said real-time 3D ultrasound images with the pre-acquired 3D images by using said reference pattern or patterns or said object or objects.

2. The method according to claim 1, wherein the first 3D ultrasound images acquired in real-time and the 3D ultrasound images in the background comprise both imaging data and Doppler data, the Doppler data containing ultrasound information obtained by one or more of the techniques selected from the group consisting of Color Doppler, Power Doppler, or Color Coded Doppler, and by using said techniques individually or combined for a continuous co-registration with the same reference pattern identified in the pre-acquired 3D image.

3. The method according to claim 1, wherein the pre-acquired image is a 3D image and said first real-time ultrasound images (1) are 3D ultrasound images.

4. The method according to claim 1, wherein the fusion tomographic images are 2D images and comprise a view of a real-time image (1) along a predetermined scanning plane (10) and a corresponding view, reconstructed based on the co-registration, of the pre-acquired image.

5. The method according to claim 4, wherein the co-registration (63) is performed by identifying, as the reference pattern or object, a plurality of markers lying on a registration plane (11) of the pre-acquired image and by identifying corresponding markers in the first real-time ultrasound image (1).

6. The method according to claim 5, wherein the markers are blood vessels.

7. The method according to claim 1, further comprising the following steps:

identifying in the pre-acquired 3D image a volume or section plane comprising the at least one reference pattern or object therein;

acquiring at least one 3D ultrasound image by a quick acquisition and identifying inside at least one 3D ultrasound image the at least one reference pattern or object;

performing a registration of the 3D ultrasound images with the pre-acquired 3D images on based on said reference pattern or said object;

defining a plane or volume corresponding to a view of an object or to an anatomical district to be examined within the 3D ultrasound image acquired in real-time and in the pre-acquired 3D image registered with each other, the plane or volume not coinciding with the volume or section plane containing the reference pattern or object for performing the registration;

continuing with acquisition of the 3D ultrasound image and reconstruction of the real-time ultrasound image in said plane or in said volume corresponding to the view of an object or to an anatomical district to be examined and performing a fusion with the corresponding image along said plane or in said volume of the pre-acquired 3D image; and

continuing with the acquisition in the background of the image data of the 3D ultrasound images and with using in background information or data of the 3D ultrasound images acquired in real-time for maintaining the registration between real-time ultrasound images and pre-acquired images by continuing to perform in the background a registration process for each 3D ultrasound image acquired in real-time and in the background and the pre-acquired 3D image by using the volume or section plane comprising the at least one reference pattern or the at least one object therein.

8. The method according to claim 1, further comprising the step of performing at least one first quick acquisition of a 3D ultrasound image and an automatic registration algorithm operating in the background, and performing a fusion based on blood vessels of the brain shown by magnetic resonance with hemodynamic 3D Doppler information of the brain.

9. The method according to claim 1, wherein 3D ultrasound acquisition in real-time is performed with plane wave transmission/imaging techniques.

10. The method according to claim 1, wherein the step of registering (63) comprises an assessment and an consequent adaptation of size change of one or more anatomical structures between a time of pre-acquired image acquisition and the time of real-time image (1) acquisition.

11. The method according to claim 1, wherein a region of interest is fetal head (2) and the reference pattern or object is a bone structure of the skull or the Circle of Willis.

12. The method according to claim 1, wherein the step of acquiring the first 3D ultrasound image is performed with a probe having a two-dimensional array of transducers.

14. The device according to claim 12, wherein the ultrasound probe is an array ultrasound probe.

13. A device for acquiring and displaying ultrasound images, comprising:

a probe (3) provided with one or more electroacoustic transducers;

a unit (57) transmitting an ultrasonic beam through the transducers into a body under examination;

a unit (58) receiving and processing ultrasound signals received from the transducers for generating real-time images;

a tracking system (53) for the probe (3);

a registration unit (54) registering an acquired real-time ultrasound image (1) with a pre-acquired image, to combine a coordinate system of the body under examination, a coordinate system of the probe and a coordinate system of the pre-acquired image into a single coordinate system; and

a displaying unit (56) displaying a sequence of fusion images, each fusion image comprising the corresponding real-time image and the pre-acquired image,

wherein the registration unit (54) operates in real time for each or some of the real-time images.