Wide field raman imaging apparatus and associated methods

Abstract

Apparatus and methods are presented herein that permit real-time, accurate detection of residual tumor in the operating room. The Raman-based wide-field imaging apparatus and methods described herein permit real-time imaging of tumor-targeted R-MR nanoparticles over a wide field.

We claim: 
     
         1 . A wide field Raman imaging apparatus comprising:
 at least one light source for producing excitation light;   optics for directing the excitation light onto and/or into a target tissue;   a detector for detecting Raman scattered photons emanating from the target tissue following illumination by the excitation light, the Raman scattered photons indicative of the presence of a Raman reporter in and/or upon the target tissue; and   a processor configured to process data corresponding to the Raman scattered photons detected from the target tissue and to produce an image depicting a wide field corresponding to the target tissue, the image visually indicating position and/or intensity of the Raman reporter within the wide field.   
     
     
         2 . The apparatus of  claim 1 , wherein the at least one light source, the detector, and the processor are configured to produce a substantially real-time series of images visually indicating position and/or intensity of the Raman reporter within the wide field. 
     
     
         3 . The apparatus of  claim 2 , wherein the processor is configured to produce each image of the real-time series of images by obtaining one or more monochromatic images within a given short interval of time (e.g., 500 milliseconds or less, e.g., 50 milliseconds or less), each monochromatic image obtained at a wavelength corresponding to a spectral peak characteristic of the Raman reporter, and to use the one or more monochromatic images to produce the image in the real-time series indicating the position and/or intensity of the Raman reporter within the wide field during the given short interval of time. 
     
     
         4 . The apparatus of any one of the preceding claims, wherein the wide field is at least 100 cm 2  in area (e.g., at least 300, 500, 1000, or 1200 cm 2 ). 
     
     
         5 . The apparatus of any one of the preceding claims, wherein the at least one light source comprises a tunable laser source. 
     
     
         6 . The apparatus of any one of the preceding claims, wherein the optics comprise a tunable laser line filter (LLF) and/or a tunable notch filter (NF) (e.g., said filter(s) comprising tandem thick volume Bragg gratings). 
     
     
         7 . The apparatus of any one of the preceding claims, wherein the detector is a hyperspectral imager with a spatial resolution no greater than about 10 mm 2  (e.g., from 0.1 mm 2  to 3 mm 2 , e.g., about 1 mm 2 ). 
     
     
         8 . The apparatus of any one of the preceding claims, wherein the detector comprises an optical pathway configured to allow x-y imaging of the Raman reporter within the wide field regardless of depth (z) of the Raman reporter in relation to the detector. 
     
     
         9 . The apparatus of any one of the preceding claims, further comprising a visual display for viewing the image. 
     
     
         10 . The apparatus of any one of the preceding claims, wherein the processor is configured to produce a substantially real-time series of images and transmit the images for display on a personal image display (e.g., worn by the surgeon), such that the series of images can be displayed on, in, or through a transparent display that superimposes the displayed series of images over a corresponding view of the wide field. 
     
     
         11 . The apparatus of  claim 10 , wherein the processor is configured to track the position of the personal image display and compensate the series of images for movement of the display (e.g., movement of the wearer of the display), accordingly (e.g., by tracking the location of markers affixed on or near the patient as they appear within a field of view of the personal image display). 
     
     
         12 . The apparatus of any one of the preceding claims, further comprising a visual display, wherein the visual display is an adjustable tablet-shaped screen positionable in relation to the target tissue of a patient in an operating bed, wherein the optics for directing the excitation light onto and/or into the target tissue are positioned on the side of the tablet-shaped screen facing the operating bed, and the image is displayed on the side of the tablet-shaped screen facing away from the operating bed so as to be viewable by a surgeon. 
     
     
         13 . The apparatus of any one of the preceding claims, wherein the light source for producing excitation light comprises one or more lasers, and wherein the optics for directing the excitation light onto and/or into the target tissue are configured to disperse the excitation light evenly over the wide field corresponding to the target tissue. 
     
     
         14 . A method for performing wide field Raman imaging of target tissue of a patient during a surgical procedure, the method comprising:
 administering a first Raman reporter to the patient (e.g., intravenously, topically, intraarterially, intratumorally, intranodally, via lymphatic vessels, etc.);   illuminating the target tissue with excitation light;   detecting Raman scattered photons emanating from the target tissue following illumination by the excitation light, the Raman scattered photons indicative of the presence of the first Raman reporter in and/or upon the target tissue;   obtaining, by the processor of a computing device, an image depicting a wide field corresponding to the target tissue, the image visually indicating position and/or intensity of the first Raman reporter within the wide field; and   displaying the image.   
     
     
         15 . The method of  claim 14 , wherein the first Raman reporter accumulates within and/or upon cancerous, diseased, and/or otherwise abnormal portions of the target tissue prior to the illuminating and detecting step. 
     
     
         16 . The method of  claim 14  or  15 , comprising obtaining, by the processor of the computing device, a substantially real-time series of images visually indicating position and/or intensity of the first Raman reporter within the wide field and displaying the series of images in real-time. 
     
     
         17 . The method of  claim 16 , comprising obtaining, for each image of the real-time series of images, by the processor of the computing device, one or more monochromatic images within a given short interval of time (e.g., 500 milliseconds or less, e.g., 50 milliseconds or less), each monochromatic image obtained at a wavelength corresponding to a spectral peak characteristic of the Raman reporter, and using the one or more monochromatic images to produce the image in the real-time series indicating the position and/or intensity of the Raman reporter within the wide field during the given short interval of time. 
     
     
         18 . The method of  claim 16  or  17 , comprising displaying the real-time series of images at a frame rate at least 10 frames per second (e.g., 20 to 25 frames per second). 
     
     
         19 . The method of any one of  claims 14  to  18 , wherein the first Raman reporter comprises Raman-MRI (R-MR) nanoparticles. 
     
     
         20 . The method of any one of  claims 14  to  18 , wherein the first Raman reporter comprises SERRS nanoparticles. 
     
     
         21 . The method of any one of  claims 14  to  20 , comprising administering a second Raman reporter to the patient with different Raman signature than the first Raman reporter, wherein the detected Raman scattered photons are indicative of the presence of the first Raman reporter and the second Raman reporter in and/or upon the target tissue, and wherein the image visually indicates position and/or intensity of the first Raman reporter and the second Raman reporter within the wide field in a manner such that the first Raman reporter is distinguishable from the second Raman reporter. 
     
     
         22 . The method of any one of  claims 14  to  21 , wherein the wide field is at least 100 cm 2  in area (e.g., at least 300, 500, 1000, or 1200 cm 2 ). 
     
     
         23 . The method of any one of  claims 14  to  22 , comprising displaying the image on a visual display, wherein the visual display is an adjustable tablet-shaped screen positionable in relation to the target tissue of a patient in an operating bed, wherein the image is displayed on the side of the tablet-shaped screen facing away from the operating bed such that it is viewable by a surgeon during a surgical procedure. 
     
     
         24 . The method of any one of  claims 14  to  23 , comprising producing, by the processor of the computing device, a substantially real-time series of images and displaying the images on a personal image display (e.g., worn by a surgeon operating on the patient), such that the series of images are displayed on, in, or through a transparent display that superimposes the displayed series of images over a corresponding view of the wide field. 
     
     
         25 . The method of  claim 24 , comprising tracking, by the processor of the computing device, the position of the personal image display, and compensating the series of images for movement of the display (e.g., movement of the wearer of the display), accordingly (e.g., by tracking the location of markers affixed on or near the patient as they appear within the field of view of the personal image display). 
     
     
         26 . A system comprising:
 an excitation light source for directing excitation light onto or into a target tissue;   an instrument (e.g., hand-held instrument) operably linked to the excitation light source, the instrument comprising:
 optics for directing the excitation light onto or into the target tissue; 
   a detector for detecting Raman scattered photons emanating from the target tissue, said Raman scattered photons resulting from illumination with the excitation light (e.g., detecting a Raman signal); and
 a resector/ablator mechanism; 
   a processor (e.g., a Raman spectrometer and associated computer processor and/or software) configured to process data corresponding to the Raman scattered photons detected from the target tissue (e.g., the Raman signal); and   a resector/ablator controller operably linked to the processor and operably linked to the resector/ablator mechanism.   
     
     
         27 . The system of  claim 26 , wherein the excitation light source is a laser. 
     
     
         28 . The system of  claim 26  or  27 , wherein the excitation light has a wavelength of about 500 nm to about 10 μm. 
     
     
         29 . The system of any one of the preceding claims, wherein the instrument is an endoscopic instrument. 
     
     
         30 . The system of any one of the preceding claims, wherein the instrument comprises optics for imaging. 
     
     
         31 . The system of any one of the preceding claims, wherein the resector/ablator mechanism comprises a laser. 
     
     
         32 . The system of  claim 31 , wherein the laser of the resector/ablator mechanism is a CO 2  laser. 
     
     
         33 . The system of any one of the preceding claims, wherein the resector/ablator mechanism is a mechanical resector, an electro-cautery mechanism, a cryoablation mechanism, and/or a radiofrequency ablation mechanism. 
     
     
         34 . The system of any one of the preceding claims, wherein the resector/ablator controller is configured to activate the resector/ablator mechanism to resect, ablate, and/or destroy tissue at a given location only if Raman scattered photons detected from the given location indicate the presence of a Raman reporter (e.g., SERS nanoparticles, SERRS nanoparticles, or intrinsic species). 
     
     
         35 . The system of any one of the preceding claims, further comprising a suction vacuum operably linked to the instrument. 
     
     
         36 . A method of resecting, ablating, and/or destroying diseased tissue, the method comprising:
 positioning an instrument in relation to a first location (e.g., (x,y,z) or (x,y) location) of a target tissue of a subject (e.g., human or animal), the instrument comprising:   optics for directing excitation light onto or into the target tissue at a given location;
 a detector for detecting Raman scattered photons emanating from the target tissue (e.g., detecting a Raman signal) at the given location; and 
 a resector/ablator mechanism; 
   detecting the Raman scattered photons emanating from the first location of the target tissue (e.g., detecting the Raman signal);   analyzing the detected Raman scattered photons emanating from the first location (e.g., analyzing the Raman signal) to determine whether the detected photons are indicative of the presence of a Raman reporter (e.g., SERS nanoparticles, SERRS nanoparticles, or intrinsic species) at the first location; and   activating the resector/ablator mechanism (e.g., via a resector/ablator controller) to resect the target tissue at the first location only if the analyzed photons from the first location are determined to be indicative of the presence of the Raman reporter at the first location.   
     
     
         37 . The method of  claim 36 , further comprising:
 deactivating the resector/ablator mechanism prior to repositioning of the instrument in relation to a second location of the target tissue (e.g., wherein the second location of the target tissue is adjacent to the first location);   detecting the Raman scattered photons emanating from the second location of the target tissue;
 analyzing the detected Raman scattered photons emanating from the second location to determine whether the detected photons are indicative of the presence of a Raman reporter (e.g., SERS nanoparticles, SERRS nanoparticles, or intrinsic species) at the second location; and 
 activating the resector/ablator mechanism to resect, ablate, and/or destroy the target tissue at the second location only if the analyzed photons from the second location are determined to be indicative of the presence of the Raman reporter at the second location. 
   
     
     
         38 . The method of  claim 36  or  37 , further comprising administering nanoparticles (e.g., SERS nanoparticles) to the subject prior to implementation of the instrument (e.g., allowing accumulation of the nanoparticles in regions associated with disease). 
     
     
         39 . The method of any one of  claims 36 - 38 , further comprising scanning the subject prior to implementation of the instrument to confirm the absence of nanoparticles from healthy (e.g., normal, non-cancerous) tissue. 
     
     
         40 . The method of any one of  claims 36 - 39 , wherein the instrument is operably linked to an excitation light source. 
     
     
         41 . The method of  claim 40 , wherein the excitation light source is a laser. 
     
     
         42 . The method of any one of  claims 36 - 41 , wherein the excitation light has a wavelength of about 500 nm to about 10 μm. 
     
     
         43 . The method of any one of  claims 36 - 42 , wherein the instrument is an endoscopic device. 
     
     
         44 . The method of any one of  claims 36 - 43 , wherein the instrument comprises optics for imaging. 
     
     
         45 . The method of any one of  claims 36 - 44 , wherein the resector/ablator mechanism comprises a laser. 
     
     
         46 . The method of  claim 45 , wherein the laser of the resector/ablator mechanism is a CO 2  laser. 
     
     
         47 . The method of any one of  claims 36 - 46 , wherein the resector/ablator mechanism is a mechanical resector, an electro-cautery mechanism, a cryoablation mechanism, and/or a radiofrequency ablation mechanism. 
     
     
         48 . The method of any one of  claims 36 - 47 , wherein the analyzing step comprises using a computer processor (e.g., a Raman spectrometer and associated computer processor and/or software) to process data corresponding to the detected Raman scattered photons. 
     
     
         49 . The method of any one of  claims 36 - 48 , further comprising removing resected tissue. 
     
     
         50 . The method of any one of  claims 36 - 49 , wherein the method is an in vivo method.