BIOLOGICAL INFORMATION IMAGING APPARATUS, BIOLOGICAL INFORMATION ANALYZING METHOD, AND BIOLOGICAL INFORMATION IMAGING METHOD

• US 20090002685A1
• Filed: 09/04/2008
• Published: 01/01/2009
• Est. Priority Date: 05/15/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Fukutani, Kazuhiko, Asao, Yasufumi, Nakajima, Takao, Den, Toru
• Granted Patent: US 7,864,307 B2
• Time in Patent Office: Days
• US Class Current: 356/72
• CPC Class Codes: A61B 5/0035 adapted for acquisition of images from more than one imaging mode, e.g. combining MRI and optical tomography
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements

Abstract

A biological information imaging apparatus includes: a light source; an acoustic, wave detector that detects an acoustic wave generated from a light absorption material in a living body that has absorbed a part of energy of light irradiated from the light source to the living body, and converts it into a first electric signal; a photodetector that detects optical intensity of a portion of the light irradiated from the light source to the living body and propagating in the living body, and converts it into a second electric signal; and a calculation unit that calculates optical property distribution information on the living body by making use of an analytical result of one of the first electric signal and the second electric signal for analysis of the other electric signal.

Claims

1. A biological information imaging apparatus comprising:

a light source;

an acoustic wave detector that detects an acoustic wave generated from a light absorption material in a living body that has absorbed a part of energy of light irradiated from said light source to said living body, and converts the acoustic wave into a first electric signal;

a photodetector that detects optical intensity of a portion of the light irradiated from said light source to said living body and propagating in said living body, and converts the optical intensity into a second electric signal; and

a calculation unit that calculates optical property distribution information on said living body by making use of an analytical result of one of the first electric signal and the second electric signal for analysis of the other electric signal.

2. The biological information imaging apparatus according to claim 1, wherein

said calculation unit calculates second optical property distribution information by making use of first optical property distribution information that is an analytical result of the first electric signal for the analysis of the second electric signal.

3. The biological information imaging apparatus according to claim 2, wherein

the first optical property distribution information is either of a size of said light absorption material, a position in which said light absorption material exists, and an optical energy absorption density distribution of said light absorption material.

4. The biological information imaging apparatus according to claim 3, wherein

the second optical property distribution information is either of an amount of light irradiated to said light absorption material, an absorption coefficient of said light absorption material, and an effective scattering coefficient of said light absorption material.

5. The biological information imaging apparatus according to claim 1, wherein

said calculation unit calculates an absorption coefficient distribution of said light absorption material by making use of an amount of light irradiated to said light absorption material that is an analytical result of the second electric signal for the analysis of the first electric signal.

6. The biological information imaging apparatus according to claim 1, wherein

said light absorption material in said living body is a tumor or a blood vessel in said living body.

7. The biological information imaging apparatus according to claim 1, wherein

said acoustic wave detector is configured to be capable of detecting an acoustic wave in a plurality of locations.

8. The biological information imaging apparatus according to claim 1, wherein

said photodetector is configured to be capable of detecting the intensity of light in a plurality of locations.

9. The biological information imaging apparatus according to claim 1, wherein

said light source comprises one or more light sources, of which at least one is designed as a light source for generating pulsed light.

10. The biological information imaging apparatus according to claim 9, wherein

said light source is composed of at least two light sources which comprise a first light source for generating pulsed light, and a second light source for generating light of a waveform different from that of said pulsed light;

said acoustic wave detector is configured to be capable of converting the light irradiated from said first light source to said living body into the first electric signal; and

said photodetector is configured to be capable of converting the light irradiated from said second light source to said living body into the second electric signal.

11. The biological information imaging apparatus according to claim 1, wherein

said photodetector is configured to be capable of detecting light, which has a wavelength different from that of original light of said light source and is emitted from said light absorption material in said living body that has absorbed a part of energy of the light irradiated from said light source to said living body.

12. The biological information imaging apparatus according to claim 11, wherein

said light absorption material in said living body is a contrast agent introduced into said living body.

13. The biological information imaging apparatus according to claim 1, wherein

said light source has a wavelength in the range of not less than 400 nm and not more than 1,600 nm.

14. A biological information analyzing method for analyzing electric signals that are obtained from an acoustic wave detector and a photodetector, wherein said acoustic wave detector detects an acoustic wave generated from a light absorption material in a living body that has absorbed a part of energy of light irradiated from a light source to said living body, and converts the acoustic wave into a first electric signal, and said photodetector detects optical intensity of a portion of the light irradiated from said light source to said living body and propagating in said living body, and converts the optical intensity into a second electric signal, said method comprising the steps of:

analyzing an optical energy absorption density distribution from the first electric signal; and

calculating an absorption coefficient distribution or an effective scattering coefficient distribution of said light absorption material by analyzing the second electric signal with the use of the optical energy absorption density distribution.

15. The biological information analyzing method according to claim 14, further comprising the step of:

calculating an elastic property distribution by using the absorption coefficient distribution of said light absorption material.

16. A biological information analyzing method for analyzing electric signals that are obtained from an acoustic wave detector and a photodetector, wherein said acoustic wave detector detects an acoustic wave generated from a light absorption material in a living body that has absorbed a part of energy of light irradiated from a light source to said living body, and converts the acoustic wave into a first electric signal, and said photodetector detects optical intensity of a portion of the light irradiated from said light source to said living body and propagating in said living body, and converts the optical intensity into a second electric signal, said method comprising the steps of:

calculating an optical property distribution of said living body by making use of an analytical result of one of the first electric signal and the second electric signal for analysis of the other electric signal.

17. A biological information imaging method comprising the steps of:

acquiring distribution information on an optical property of an object to be imaged in a living body by measuring, at a plurality of locations, diffused light of light entering said living body; and

imaging information on said object to be imaged by using the distribution information;

wherein said imaging step is performed by using information based on an acoustic wave output from said object to be imaged that has absorbed a part of light irradiated to said object to be imaged.

18. A biological information imaging method comprising the steps of:

acquiring distribution information on an optical property of an object to be imaged in a living body by measuring, at a plurality of locations, an acoustic wave generated from said object to be imaged in said living body that has absorbed a part of energy of light entering said living body; and

imaging information on said object to be imaged by using the distribution information;

wherein said imaging step is performed by using information based on diffused light that has propagated through said object to be imaged.

19. A biological information imaging apparatus comprising:

a light source;

an acoustic wave detector that receives an acoustic wave generated from a light absorption material in a living body that has absorbed a part of energy of light irradiated from said light source to said living body, and outputs a first electric signal in accordance with a sound pressure of the acoustic wave thus received;

a photodetector that receives propagation light of light irradiated from said light source or another light source to said living body, and outputs a second electric signal in accordance with intensity of the propagation light thus received; and

a calculation unit that calculates optical property distribution information on said living body by making use of an analytical result of one of the first electric signal and the second electric signal for analysis of the other electric signal.