Method and apparatus for obtaining an optical tomographic image of a sentinel lymph node

• US 6,636,755 B2
• Filed: 09/26/2001
• Issued: 10/21/2003
• Est. Priority Date: 09/26/2000
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Toida, Masahiro
• Primary Examiner(s): Shaw, Shawna J.
• Application Number:
  US09/962,195
• Publication Number:
  US 20020037252A1
• Time in Patent Office: 755 Days
• Field of Search: 600/431, 600/436, 600/473, 600/476, 600/160, 600/475, 600/407, 356/345, 356/450, 356/456, 424/9.6, 250/458.1, 250/459.1
• US Class Current: 600/407
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/418 lymph vessels, ducts or nodes
• CPC Class Codes: A61K 49/0034 Indocyanine green, i.e. ICG, cardiogreen
• CPC Class Codes: G01B 9/02003 using beat frequencies
• CPC Class Codes: G01B 9/0203 With imaging systems
• CPC Class Codes: G01B 9/02031 With non-optical systems, e.g. tactile
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence

Abstract

An apparatus for obtaining a cellular image to be used in performing a test for pathology of the sentinel lymph node, which is the first lymph node a cancer metastasizes to. The gamma radiation emitted from a near-infrared fluorescent colorant injected in advance into the vicinity of a tumor is detected by use of a gamma-probe. A fiber coupler separates the low-coherence light emitted from the light source of an OCT portion (Optical Coherence Tomography) into a signal-light to be projected onto the sentinel lymph node and a reference-light whose wavelength is slightly shifted. The signal-light is projected onto the sentinel lymph node, and interference is caused between the signal-light reflected from a predetermined depth within the sentinel lymph node and the reference-light. A balance differential detector measures the intensity of the interference-light, and a cellular level ultra high-resolution optical tomographic image of the sentinel lymph node is obtained.

Claims

1. A method of obtaining a sentinel lymph node optical tomographic image comprising the steps of:

detecting a sentinel lymph node which exists in the vicinity of a target subject,

scanning the detected sentinel lymph node with a signal-light which is a low-coherence light having a coherence length of 5 um or less, and

obtaining an ultra high-resolution optical tomographic image of the sentinel lymph node by using the signal-light reflected from a predetermined depth of said sentinel lymph node and a reference-light having a slight difference in frequency with respect to said signal-light.

2. A method of obtaining a sentinel lymph node optical tomographic image as defined in claim 1, wherein the detecting of the sentinel lymph node comprises the steps of

injecting in advance a near-infrared colorant that emits fluorescent light having a wavelength near the near-infrared wavelength band into the vicinity of a target subject including the sentinel lymph node,

irradiating said target subject including the sentinel lymph node with an excitation light having a wavelength within the wavelength band causing excitation of said near-infrared fluorescent colorant,

obtaining a fluorescent-light image formed of near-infrared fluorescent light emitted from said target subject upon the irradiation thereof by said excitation light, and

detecting the sentinel lymph node based on said obtained fluorescent-light image.

3. A method of obtaining a sentinel lymph node optical tomographic image as defined in claim 2, wherein

the position of the detected sentinel lymph node is matched with the scanning-position to be scanned with the signal-light.

4. The method of claim 2, wherein the fluorescent image of the target subject is displayed by a device including a charge coupled device (CCD).

5. The method of claim 1, wherein the wavelength of the low coherence light falls between a range 600-1000 nm.

6. The method of claim 5, wherein the scanning comprises scanning the signal light along a linear path to scan the sentinel lymph node.

7. The method of claim 6, wherein the scanning of the lymph node and obtaining the image of the lymph node are performed in vivo.

8. The method of claim 1 wherein detection of the sentinel lymph node comprises injection of a radioisotope to permeate the vicinity of the target substrate.

9. An apparatus for obtaining a sentinel lymph node optical tomographic image, comprising

sentinel lymph node detecting means for detecting a sentinel lymph node which exists in the vicinity of a target subject, and

an OCT means for scanning the detected sentinel lymph node with a signal-light, which is a low-coherence light having a coherence length of 5 um or less, and obtaining an ultra high-resolution optical tomographic image of the sentinel lymph node by using the reflected-light reflected from a predetermined depth of said sentinel lymph node and a reference-light having a slight difference in frequency with respect to said signal-light.

10. An apparatus for obtaining a sentinel lymph node optical tomographic image as defined in claim 9, wherein

the sentinel lymph node detecting means comprises an excitation light emitting means for projecting onto the target subject an excitation light having a wavelength within the wavelength band causing excitation in a near-infrared fluorescent colorant that emits fluorescent light having a wavelength near the near-infrared wavelength band and which has been injected in advance into the vicinity of a target subject including the sentinel lymph node,

an image obtaining means for obtaining a fluorescent-light image formed of the near-infrared fluorescent light emitted from said target subject upon the irradiation thereof by said excitation light, and

a detecting means for detecting, based on the fluorescent-light image obtained by said image obtaining means, the sentinel lymph node.

11. An apparatus for obtaining a sentinel lymph node optical tomographic image as defined in claim 10, wherein

the OCT means is provided with a scanning-position control means for matching the scanning-position to be scanned by the signal-light to the position of the sentinel lymph node detected, based on the fluorescent-light image, by the detecting means.

12. An apparatus for obtaining a sentinel lymph node optical tomographic image as defined in either of claims 9, 10, or 11, wherein

the wavelength of the low-coherence light falls within the 600-1700 nm wavelength range.