Method and apparatus for ultrasound image reconstruction

• US 6,228,028 B1
• Filed: 11/07/1997
• Issued: 05/08/2001
• Est. Priority Date: 11/07/1996
• Status: Expired due to Term

• Current Assignee: TomTec Imaging Systems GmbH (Koninklijke Philips N.V.)
• Original Assignee: TomTec Imaging Systems GmbH (Koninklijke Philips N.V.)
• Inventors: Klein, Peter, Marquart, Markus, Mumm, Bernhard
• Primary Examiner(s): Casler, Brian L.
• Assistant Examiner(s): PATEL, MAULIN M
• Application Number:
  US08/966,430
• Time in Patent Office: 1,278 Days
• Field of Search: 600/437, 600/447, 600/443, 600/449, 128/916
• US Class Current: 600/437
• CPC Class Codes: G01S 15/8993 Three dimensional imaging systems
• CPC Class Codes: G01S 7/52025 for pulse systems G01S7/52034 takes precedence
• CPC Class Codes: G01S 7/5205 Means for monitoring or calibrating

Abstract

The ultrasound imaging system and method of the present invention defines the gray-scale value and other parameters for each of a plurality of image elements in an output volume by determining all of the image information in the scanning planes that is contained within a defined portion of the output volume (which contains the image element) and thereafter simultaneously analyzing the selected image information. These steps are repeated for each of the image elements in the output volume.

Claims

1. A method for constructing a three- or four-dimensional image describing an object, comprising:

(a) passing ultrasonic energy through at least a portion of an object and thereby generating image information describing the object, the image information corresponding to a plurality of ultrasonic regions having a predetermined geometric configuration;

(b) determining an ordering for a plurality of image elements of a three- or four-dimensional output volume, wherein each of said image elements has a predetermined size;

(c) determining the image information in at least one of the plurality of ultrasonic regions that is within a predetermined proximity of or within a first image element of the three- or four-dimensional output volume to define a first subset of image information corresponding to the first image element, wherein the output volume includes a plurality of image elements;

(d) assigning, based on one or more of the items in the first subset of image information, a gray scale value to the first image element; and

(e) repeating, in accordance with the ordering of step (b), steps (c) and (d) for each of the other image elements in the output volume to construct the three- or four-dimensional image of the object.

2. The method of claim 1, wherein the generating step comprises:

passing an ultrasound probe over the object, wherein the position of the ultrasound Probe is determined by a position sensor attached to the ultrasound probe and the plurality of ultrasonic regions correspond to a plurality of intersecting image planes.

3. The method of claim 2, wherein each of the plurality of image planes includes a plurality of pixels and each pixel has at least one of a height and width and wherein a dimension of the image elements in the output volume is a function of the at least one of a height and width.

4. The method of claim 1, wherein the first image element is one of a voxel or toxel and, in the determining step (c), image information in each of the plurality of ultrasonic regions is considered in defining the first subset of image information.

5. The method of claim 1, wherein the assigning step comprises the substep of:

filtering the first subset of image information to define a second set of image information that is derived from the first subset of image information, wherein the second subset of image information is different from the first subset of image information.

6. The method of claim 5, wherein in the filtering substep the gray scale value is assigned to the first image element of the output volume, the gray scale value being related to a plurality of gray scale values in the first subset of image information.

7. The method of claim 1, wherein the assigning step is performed using at least one of a first found algorithm, a closest distance algorithm, a weighted average algorithm, and a last found algorithm.

8. The method of claim 1, wherein the plurality of ultrasonic regions correspond to a plurality of ultrasound beams and the image information includes one or more of the number of each of the plurality of ultrasound beams, the type of probe, and the spatial position of each ultrasound beam.

9. The method of claim 1, wherein the image information includes at least one time stamp.

10. The method of claim 1, further comprising the step of:

filtering the image information based on the temporal distribution of image information relative to the cardiac cycle of a patient.

11. The method of claim 1, further comprising the steps of:

monitoring an ECG signal during the passing step to generate a plurality of cardiac signals;

converting the cardiac signals into digital values;

comparing each of the digital values to a threshold level to identify contraction of heart muscles and relaxation of heart muscles;

determining the time intervals between contraction of the heart muscles;

based on the step of determining the time intervals, selecting a time interval; and

rejecting image information falling outside of the time interval.

12. The method of claim 1, further comprising the step of:

filtering the image information based on the temporal distribution of the image information relative to the respiratory cycle of a patient.

13. The method of claim 1, further comprising the steps of:

monitoring the respiration phase of a patient during the passing step to generate a plurality of respiratory signals;

converting the respiratory signals into digital values;

comparing each of the digital values to a threshold level to identify contraction of diaphragm muscles and relaxation of diaphragm muscles;

determining the time intervals between contraction of the diaphragm muscles;

based on the step of determining the time intervals, selecting a time interval; and

rejecting image information falling outside of the time interval.

14. The method of claim 1, further comprising before step (c), selecting an algorithm for the assigning step that is at least one of the following:

first found algorithm, closest distance algorithm, weighted average algorithm, and last found algorithm.

15. A system for constructing a three- or four-dimensional image describing an object, comprising:

an emitter for passing ultrasonic energy through at least a portion of an object and a receiver for receiving reflected ultrasonic energy to form image information describing the object and corresponding to a plurality of ultrasonic regions having a predetermined geometric configuration,

means for determining an ordering for a plurality of image elements of a three- or four-dimensional output volume, wherein each of said image elements has a predetermined size;

means for determining the image information in at least one of the plurality of ultrasonic regions that is within a predetermined proximity of or within a first image element to define a first subset of image information corresponding to the first image element; and

means for analyzing one or more of the items in the first subset of image information to assign a gray scale value to the first image element.

16. The system of claim 15, wherein a position sensor receiver is attached to the emitter, the position sensor receiver determining the position of the emitter in space.

17. The system of claim 15, wherein each ultrasonic region includes a plurality of pixels and each pixel has at least one of a height and width and wherein a dimension of the first image element of the output volume is a function of the at least one of a height and width.

18. The system of claim 15, wherein the image information includes location coordinates relative to a reference axis and the output volume is defined by the reference axis and the determining means comprises means for identifying the image information that is located within the predetermined proximity of or within each image element to define each of the subsets of image information corresponding to each of the plurality of image elements.

19. The system of claim 15, wherein the means for analyzing includes:

means for processing the first subset of image information to define a second set of image information that is derived from the first subset of image information, wherein the second subset of image information is different from the first subset of image information.

20. The method of claim 19, wherein the image information is contained in a plurality of predetermined regions and, in substep (ii), each of the plurality of predetermined regions is considered in determining a gray scale value for each of the subvolumes.

21. The system of claim 19 wherein the processing means assigns the gray scale value to the first image element, the gray scale value being related to a plurality of gray scale values in the first subset of image information.

22. A method for constructing a three- or four-dimensional image describing an object, comprising:

(a) passing an ultrasound probe over an object to generate image information describing a characteristic of an object,

(b) determining an ordering for a plurality of subvolumes of an output volume, wherein each of said subvolumes has a predetermined size;

(c) performing for each subvolume, in a manner related to the predetermined ordering, one or more of the following steps;

(i) selecting a predetermined region of image information having a predetermined geometric configuration; and

(ii) determining a gray scale value for said subvolume according to the image information in the predetermined region that are located within a predetermined proximity of or within said subvolume.

23. The method of claim 22, wherein the image information is located outside of the subvolume and within the predetermined proximity of the subvolume to define a three- or four-dimensional representation of the object.

24. A method for constructing a three- or four-dimensional image describing tissue of a patient, comprising:

(a) generating image information describing the tissue and corresponding to a plurality of image planes, wherein the image information comprises a plurality of items of image information,

(b) monitoring at least one of the cardiac and respiratory cycles of the patient;

(c) assigning a time stamp to each of the plurality of items of image information;

(d) providing a set of temporal signals from the monitoring step;

(e) generating from the image information and the corresponding time stamps at least one output volume, the at least one output volume including a plurality of image elements;

(f) thereafter filtering the image information based on the relationship of the time stamps corresponding to the image information to one or more selected temporal signals; and

(g) thereafter viewing an image of the tissue based on the selected image information.

25. The method of claim 24, wherein the tissue is heart tissue and the generating step comprises sorting through the plurality of items of image information based on the time stamp to provide an image of the heart tissue during a selected part of the cardiac cycle.

26. A system for constructing a three- or four-dimensional image describing an object, comprising:

an emitter for passing ultrasonic energy through at least a portion of an object;

a receiver, in communication with the emitter, for receiving reflected ultrasonic energy to form image information describing the object and corresponding to a plurality of predetermined regions, each predetermined region of image information having a predetermined geometric configuration;

a first computational component, in communication with the receiver, for determining an ordering for a plurality of subvolumes of an output volume, wherein each of the subvolumes has a predetermined size;

a second computational component, in communication with the first computational component, for selecting for each subvolume, in a manner related to the predetermined ordering, one or more of the predetermined regions of image information; and

a third computational component, in communication with the second computational component, for determining for each subvolume, in a manner related to the predetermined ordering, a gray scale value according to the image information in the predetermined region that is within a predetermined proximity of or within the subvolume.

27. The system of claim 26, wherein a position sensor receiver is attached to the emitter, the position sensor receiver determining a position of the emitter in space, and the plurality of predetermined regions correspond to a plurality of intersecting image planes.

28. The system of claim 27, wherein each image plane includes a plurality of pixels and each pixel has at least one of a height and width and wherein a dimension of the image elements in the output volume is a function of the at least one of a height and width.

29. The system of claim 26, further comprising:

a fourth computational component, in communication with at least one of the receiver, emitter, and first computational component, for assigning one or more time stamps to the image information;

a fifth computational component, in communication with at least one of the receiver, emitter, first computational component, and second computational component, for monitoring at least one of the cardiac and respiratory cycles of a patient; and

a sixth computational component, in communication with the fifth computational component, for providing a set of temporal signals.

30. The system of claim 26, further comprising:

a fourth computational component, in communication with the third computational component, for selecting an algorithm, from among a number of possible algorithms, that is at least one of the following;

first found algorithm, closest distance algorithm, weighted average algorithm, and last found algorithm.