METHOD AND APPARATUS FOR MEDICAL IMAGING USING COMBINED NEAR-INFRARED OPTICAL TOMOGRAPHY, FLUORESCENT TOMOGRAPHY AND ULTRASOUND

• US 20130109963A1
• Filed: 10/31/2011
• Published: 05/02/2013
• Est. Priority Date: 10/31/2011
• Status: Abandoned Application

• Current Assignee: University of Connecticut (State of Connecticut)
• Original Assignee: University of Connecticut (State of Connecticut)
• Inventors: Zhu, Quing
• Application Number:
  US13/285,957
• Publication Number:
  US 20130109963A1
• Time in Patent Office: Days
• US Class Current: 600/427
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• 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 5/0071 by measuring fluorescence emission
• 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 5/0091 for mammography
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14556 by fluorescence A61B5/14555 takes precedence
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: A61B 8/0825 for diagnosis of the breast, e.g. mammography
• CPC Class Codes: A61B 8/4416 related to combined acquisition of different diagnostic modalities, e.g. combination of ultrasound and X-ray acquisitions

Abstract

Methods and apparatus for medical imaging using diffusive optical tomography and fluorescent diffusive optical tomography and ultrasound are disclosed. In one embodiment, the probe comprises emitters and detectors that are inclined at an angle of about 1 to about 30 degrees to a surface of the probe that contacts tissue. In another embodiment, the scanned volume is divided into an inclusion region and a background region. Different voxel sizes are used in the inclusion region and the background region. Appropriate algorithms facilitate a reconstruction of the inclusion region to determine structural and functional features of the inclusion.

Claims

1. A method comprising:

obtaining an image of a tissue volume with a probe comprising;

an ultrasound transducer that is operative to provide an on-site estimation of inclusion size and location;

a first emitter and a first detector;

the first emitter having light of a wavelength of about 400 to about 900 nanometers;

the first detector detecting light of a wavelength of about 400 to about 900 nanometers;

a source circuit connected in operational communication to the emitter;

a detector circuit connected in operational communication to the detector; and

a central processing unit connected to the source circuit and the detector circuit;

scanning the tissue volume with light having a wavelength of about 400 to about 900 nanometers;

the tissue volume comprising a first layer and a second layer;

segmenting the scanned tissue volume into an inclusion region comprising a plurality of first voxels and a background region comprising a plurality of second voxels;

the volume of each second voxel being larger than the volume of each first voxel;

reconstructing the image using the equation (2)

[U_sd]<sub>M×

1</sub>=[W_L,W_B]<sub>M×

N</sub>×

[M_L,M_B]^T<sub>N×

1</sub>  

 

(2)

where W_L and W_B are weight matrices for the inclusion and background regions, respectively;

2. The method of claim 1, further comprising dividing the tissue volume N into N layers denoted as region of interest #1, region of interest #2, . . . and region of interest #N respectively;

and using the equation (2) to reconstruct one layer at a time to reconstruct the image.

5. The method of claim 1, wherein the inclusion region comprising a first voxel that has a volume of about 0.1×

0.1×

0.1 cubic centimeter (cm³) to about 1×

1×

1 cm³;

the background region comprising a second voxel that has dimensions of about 0.2×

0.2×

0.2 cm³ to about 2.0×

2.0×

2.0 cm³.

6. The method of claim 1, wherein the inclusion comprises a tumor, a lesion, or a cancerous region.

7. The method of claim 1, further comprising scanning the tissue volume with a plurality of lights, each light having a wavelength of about 400 to about 900 nanometers.

8. The method of claim 1, further comprising scanning the tissue volume with light having a wavelength of 690, 780 and 830 nanometers.

9. The method of claim 8, wherein the light having wavelengths of 690, 780 and 830 nanometers is emitted from laser diodes.

10. The method of claim 9, wherein the laser diodes are in operative communication with radio frequency oscillators.

11. The method of claim 10, wherein the radio frequency oscillators operate at frequencies of 350 MHz, 140 MHz and 50 MHz.

12. The method of claim 1, wherein the scanned tissue comprises fluorescence targets or dyes or fluorophores.

13. The method of claim 1, wherein the first emitter or the first detector is inclined at an angle of about 1 to about 30 degrees with respect to a surface of the probe that contacts tissue.

14. The method of claim 1, further comprising improving the accuracy of the reconstructed image using the Equation (6)

[U_sd]_M×

1=[W_L,W_B,W_S]<sub>M×

N</sub>×

[M_L,M_B,M_S]^T<sub>N×

1</sub>  

 

(6)

where W_L and W_B are absorption weight matrices for lesion and background regions, respectively;

W_S is the scattering weight matrix for the entire imaging volume;

15. The method of claim 1, further comprising estimating deoxygenated (deoxyHb), oxygenated (oxyHb) hemoglobin and total hemoglobin concentration totalHb(r′

)=deoxyHb(r′

)+oxyHb(r′

) and oxygenation saturation

3. The method of claim 3, wherein the reconstructing each layer comprises using the Equations (3), (4) and (5):

[U_sd]<sub>M×

1</sub>=[W_L(ROI#1),W_B1,W_{B1(other-t arg et-layers)},W_B(BG-layers)]×

[M_L(ROI#1),M_B1,M_{B1(other-t arg et-layers}),M_B(BG-layers)]T  

 

(3)

[U_sd]<sub>M×

1</sub>=[W_L(ROI#2),W_B2,W_{B2(other-t arg et-layers)},W_B(BG-layers)]×

[M_L(ROI#2),M_B2,M_{B2(other-t arg et-layers)}]T  

 

(4)

[U_sd]<sub>M×

1</sub>=[W_L(ROI#N),W_{BN(other-t arg et-layers)},W_B(BG-layers)]×

[M_L(ROI#N),M_BN,M_{BN(other-t arg et-layers}), M_B(BG-layers)]T  

 

(5)

where W_L(ROI#1), W_L(ROI#2), . . . , W_L(ROI#N), are weight matrices for the region of interest #1, #2 and #N respectively, and W_B1, W_B2, . . . , W_BN are weight matrices of corresponding background regions in the same depth layer. W_{B1(other-t arg et-layers)}, W_{B2(other-t arg et-layers)}, W_{BN(other-t arg et-layers)}, are weight matrices of other target layers excluding the corresponding region of interest # target layer, and W_B(BG-layers) is the weight matrix of the common background layers respectively.

4. The method of claim 3, wherein after reconstructing each layer, a total absorption matrix can be obtained as [M_L(ROI#1),M_L(ROI#2),M_B2, . . . M_L(ROI#N),M_BN,M_{BG(BG-layers)}], and an absorption distribution can be computed by dividing a corresponding voxel size in the inclusion regions and in the background regions.

16. An apparatus for medical imaging using diffusive optical tomography and fluorescent diffusive optical tomography comprising;

a probe comprising a first emitter and a first detector;

the first emitter or the first detector being inclined at an angle θ

of up to about 30 degrees to a surface of the probe that contacts tissue;

the probe comprising a an ultrasound transducer;

a source circuit connected in operational communication to the emitter;

a detector circuit connected in operational communication to the detector;

a central processing unit connected to the source circuit and the detector circuit;

a display operably connected to the central processing unit; and

,

wherein the central processing unit is capable of processing information to provide diffusive optical tomography and fluorescent diffusive optical tomography.

17. The apparatus of claim 16, wherein the ultrasound transducer emits energy having a frequency of 20,000 to a billion hertz.

18. The apparatus of claim 16, wherein the probe has a reflecting surface that contacts tissue.

19. The apparatus of claim 16, wherein the probe has a white surface.

20. The apparatus of claim 16, wherein the probe has a black surface that absorbs substantially all of the light incident upon it.