Intravascular imaging detector

• US 20060224065A1
• Filed: 04/07/2006
• Published: 10/05/2006
• Est. Priority Date: 01/04/2000
• Status: Active Grant

• Current Assignee: CMR Naviscan Corporation (Compania Mexicana de Radiologia CGR SA de CV)
• Original Assignee: Gamma Medica-Ideas (USA) Incorporated
• Inventors: Patt, Bradley E., Iwanczyk, Jan S., Hoffman, Edward J.
• Granted Patent: US 7,359,747 B2
• Time in Patent Office: Days
• US Class Current: 600/425
• CPC Class Codes: A61B 6/4057 by using radiation sources located in the interior of the body A61B6/037 takes precedence
• CPC Class Codes: A61B 6/425 using detectors specially adapted to be used in the interior of the body
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: G01T 1/161 Applications in the field of nuclear medicine, e.g. in vivo counting apparatus for radiation diagnosis A61B6/00

Abstract

An apparatus for intravascular imaging to detect and characterize early stage, unstable coronary arty plaques. The detector works by identifying and localizing plaque-binding beta-emitting radiopharmaceuticals.

Claims

1. An intravascular imaging catheter comprising:

a catheter body;

a first scintillator that generates light within a first emission spectrum;

a second scintillator that generates light within a second emission spectrum;

wherein the first emission spectrum is offset in wavelength from the second emission spectrum, wherein the first and second scintillator are disposed on the catheter body; and

an optical delivery device that can transmit light from the first scintillator and second scintillator to a photodetector.

2. The catheter of claim 1 wherein the first scintillator and second scintillator are aligned along an axis that is optically aligned with the optical delivery device.

3. The catheter of claim 2 further comprising at least one intermediate scintillator disposed between the first and second scintillators, wherein the intermediate scintillator(s) can emit a light in an emission spectrum that is offset in wavelength from the first and second emission spectrum.

4. The catheter of claim 1 wherein the first emission spectrum has a larger wavelength than the second emission spectrum

5. The catheter of claim 4 wherein the light emitted from the first scintillator passes through the second scintillators without exciting the second scintillator.

6. The catheter of claim 1 wherein the first and second emission spectrum emit light that has a wavelength between approximately 400 nanometers and 600 nanometers.

7. The catheter of claim 1 further comprising a spectrophotometer coupled to a proximal end of the optical delivery device.

8. The catheter of claim 7 wherein the spectrophotometer comprises a grating that spreads the transmitted light over a position sensitive photodetector.

9. The catheter of claim 1 wherein the optical delivery assembly comprises a first optical fiber coupled to the first scintillator and a second optical fiber coupled to the second scintillator.

10. The catheter of claim 9 wherein the first and second scintillator are distributed along a length of the catheter body, wherein the first and second scintillator are offset circumferentially from each other.

11. The catheter of claim 10 comprising at least one intermediate scintillator, wherein the intermediate scintillator(s) emits light in a spectrum that is offset from the light emitted from the first and second scintillators.

12. The catheter of claim 1 wherein the catheter comprises a lumen that 2 can receive a guidewire.

13. The catheter of claim 1 wherein the catheter body comprises a tapered distal tip.

14. The catheter of claim 1 wherein the scintillators comprise scintillating phosphors and polystyrene.

15. The catheter of claim 1 wherein the first and second scintillators each have a length between approximately two millimeters and seven millimeters.

16. The catheter of claim 1 wherein the photodetector is a photomultiplier tube.

17. The catheter of claim 1 wherein the first and second scintillators each have a stopping power to absorb at least approximately 60 keV.

18. The catheter of claim 1 wherein the diameter of the scintillators is less than approximately one millimeter.

19. A method of characterizing unstable plaque a body lumen, the method comprising:

positioning first and second scintillators at a target site in the body lumen;

generating light in at least one of the scintillators in response to radiation attached to the unstable plaque, wherein light generated in the first scintillators has a first emission spectrum and light generated in the second scintillator is in a second emission spectrum, wherein the first emission spectrum is offset in wavelength from the second emission spectrum; and

transmitting the light generated in the first and second scintillators down an optical fiber.

20. The method of claim 19 comprising separating the different wavelength light from the optical fiber.

21. The method of claim 20 comprising transmitting the separated light from the into a photodetector.

22. The method of claim 19 wherein positioning comprises advancing a catheter through a body lumen, wherein the catheter carries the first and second scintillators.

23. The method of claim 19 wherein the first and second scintillators disposed along an axis.