Image information acquiring apparatus, image information acquiring method and image information acquiring program

• US 9,202,124 B2
• Filed: 07/08/2011
• Issued: 12/01/2015
• Est. Priority Date: 07/22/2010
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Wanda, Koichiro
• Primary Examiner(s): Park, Chan
• Assistant Examiner(s): TRAN, MAI H
• Application Number:
  US13/810,423
• Publication Number:
  US 20130114859A1
• Time in Patent Office: 1,607 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 8/15 Transmission-tomography
• CPC Class Codes: G06V 10/25 Determination of region of interest [ROI] or a volume of interest [VOI]
• CPC Class Codes: G10K 15/046 using optical excitation, e.g. laser bundle

Abstract

An image information acquiring apparatus of the present invention includes an acoustic wave detector having, disposed on a reception surface thereof, a plurality of elements that detect acoustic waves generated by an object corresponding to a reconstruction area; an acoustic signal generator that generates acoustic signals that are used in image reconstruction, from the detected acoustic waves; an element selector that selects elements that are used in image reconstruction; and a reconstructor that performs image reconstruction of a point of interest using acoustic signals based on the acoustic waves detected by the selected elements, the image information acquiring apparatus being configured such that, for each selected element, there exists another selected element located at a symmetrical position with respect to a point at which the reception surface is intersected by a perpendicular line drawn from the point of interest to the reception surface.

Claims

1. An object information acquiring apparatus, comprising:

a light source;

an acoustic wave detector having an array of elements, each element configured to generate an acoustic signal based on a received photoacoustic wave induced by irradiation of an object with light from said light source;

a reconstructor configured to generate image data for a point of interest of the object from acoustic signals, from elements symmetrically positioned with respect to each other relative to a point within an area of said array, while omitting from generation of the image data an acoustic signal from an element that lies within said area but that has no symmetrically-positioned element within said area, said point in said area being a point within said array where a line perpendicular to the array and extending from said point of interest intersects said array; and

a position controller configured to move the position of said acoustic wave detector,

wherein said reconstructor is further configured to generate the image data for the point of interest using acoustic signals from elements in a virtual reception area comprising elements of said acoustic wave detector at different positions, and

wherein said reconstructor is further configured to generate the image data using acoustic signals from symmetrically positioned elements within said virtual reception area with respect to a point where a line perpendicular to said array and extending from said point of interest intersects said virtual reception area, and

wherein said position controller is configured to move said acoustic wave detector in such a manner that a part of said array at a position to which said acoustic wave detector is moved overlaps with a part of said array at another position of said acoustic wave detector, and

in a case where an element used for generation of the image data for the point of interest is included in an overlapping portion of said array, an average of acoustic signals based on the photoacoustic waves detected by the elements at said overlapping portion is determined as an acoustic signal of said element used for generating the image data for the point of interest.

2. The object information acquiring apparatus according to claim 1, wherein said area is substantially circular or square in shape with the center of said area being said point at which said line intersects said array.

5. The object information acquiring apparatus according to claim 1, further comprising a selector configured to select said acoustic signals to be used for an image reconstruction for the point of interest of the object from said array.

6. The object information acquiring apparatus according to claim 5, wherein said selector is further configured to select, as a signal used for image reconstruction, an acoustic signal generated by an element located at a position at which said line intersects said array.

7. The object information acquiring apparatus according to claim 5, wherein said selector selects a particular signal on the basis of the position of an element from which that signal is generated and said point of interest, and on the basis of the directionality of said elements, such that the selected signal is at a predetermined effective level.

8. The object information acquiring apparatus according to claim 1, wherein said elements of said array of elements are arranged two-dimensionally.

3. An object information acquiring method, comprising the steps of:

irradiating an object with light;

detecting photoacoustic waves generated by the object at different positions, by moving an acoustic wave detector having an array of elements;

generating an acoustic signal based on an photoacoustic wave detected by an element of the acoustic wave detector in said detecting step; and

generating image data for a point of interest of the object from acoustic signals, from elements symmetrically positioned with respect to each other relative to a point within an area of said array, while an acoustic signal from an element that lies within the area but that has no symmetrically-positioned element within the area is omitted, the point in the area being a point where a line perpendicular to the array and extending from the point of interest intersects the array,

wherein the image data for the point of interest is generated using acoustic signals from elements in a virtual reception area comprising elements of said acoustic wave detector at the different positions, and

wherein the image data is generated using acoustic signals from symmetrically positioned elements within said virtual reception area with respect to a point where a line perpendicular to said array and extending from said point of interest intersects said virtual reception area, and

wherein said acoustic wave detector is moved in such a manner that a part of said array at a position to which said acoustic wave detector is moved overlaps with a part of said array at another position of said acoustic wave detector, and

in a case where an element used for generation of the image data for the point of interest is included in an overlapping portion of said array, an average of acoustic signals based on the photoacoustic waves detected by the elements at said overlapping portion is determined as an acoustic signal of said element used for generating the image data for the point of interest.

4. A non-transitory, computer-readable storage medium storing, in executable form, an object information acquiring program for causing an information processing device to execute an image information acquiring method that includes the steps of:

irradiating an object with light;

detecting photoacoustic waves generated by the object at different positions, by moving an acoustic wave detector having an array of elements;

generating an acoustic signal based on a photoacoustic wave detected by an element of the acoustic wave detector in said detecting step; and

generating image data for a point of interest of the object from acoustic signals, from elements symmetrically positioned with respect to each other relative to a point within an area of the array, while an acoustic signal from an element that lies within the area but that has no symmetrically-positioned element within the area is omitted from generation of the image data, the point in the area being a point where a line perpendicular to the array and extending from the point of interest intersects the array,

wherein the image data for the point of interest is generated using acoustic signals from elements in a virtual reception area comprising elements of said acoustic wave detector at the different positions, and

wherein the image data is generated using acoustic signals from symmetrically positioned elements within said virtual reception area with respect to a point where a line perpendicular to said array and extending from said point of interest intersects said virtual reception area, and

wherein said acoustic wave detector is moved in such a manner that a part of said array at a position to which said acoustic wave detector is moved overlaps with a part of said array at another position of said acoustic wave detector, and

in a case where an element used for generation of the image data for the point of interest is included in an overlapping portion of said array, an average of acoustic signals based on the photoacoustic waves detected by the elements at said overlapping portion is determined as an acoustic signal of said element used for generating the image data for the point of interest.