We present a macroscopic line scanning Raman imaging system which has been modified to be suitable for intraoperative use. A sterilizable probe muzzle was designed to flatten the biological tissue ensuring its position at the focal plane of the Raman probe optics, removing the need for probe sterilization. The system uses a flexible imaging probe with a 1cm2 field of view to record fingerprint Raman images, mounted on an articulated arm that supports the probe weight and allows gentle contact with the tissue. Validation results obtained on porcine tissues show >95% classification accuracy between different tissue types.
Significance: Raman spectroscopy has been developed for surgical guidance applications interrogating live tissue during tumor resection procedures to detect molecular contrast consistent with cancer pathophysiological changes. To date, the vibrational spectroscopy systems developed for medical applications include single-point measurement probes and intraoperative microscopes. There is a need to develop systems with larger fields of view (FOVs) for rapid intraoperative cancer margin detection during surgery.
Aim: We design a handheld macroscopic Raman imaging system for in vivo tissue margin characterization and test its performance in a model system.
Approach: The system is made of a sterilizable line scanner employing a coherent fiber bundle for relaying excitation light from a 785-nm laser to the tissue. A second coherent fiber bundle is used for hyperspectral detection of the fingerprint Raman signal over an area of 1 cm2. Machine learning classifiers were trained and validated on porcine adipose and muscle tissue.
Results: Porcine adipose versus muscle margin detection was validated ex vivo with an accuracy of 99% over the FOV of 95 mm2 in ∼3 min using a support vector machine.
Conclusions: This system is the first large FOV Raman imaging system designed to be integrated in the workflow of surgical cancer resection. It will be further improved with the aim of discriminating brain cancer in a clinically acceptable timeframe during glioma surgery.
KEYWORDS: Imaging systems, Raman spectroscopy, Neuro-oncology, Spatial resolution, In vivo imaging, Real time imaging, Coherence imaging, Endoscopes, RGB color model, Cameras
We present the development and preliminary results of a novel intraoperative line-scanning Raman imaging system, developed for neurosurgery applications. The system records fingerprint Raman spectral images over a large field of view of 1.0cm2 through a handheld imaging probe placed in gentle contact with the interrogated tissue. With a spatial resolution of 250µm2 and an acquisition time on the order of 10s, brain structure margins can be identified within an adequate timeframe for clinical applications. The system was designed using detailed optical simulations and its performance was verified on tissue phantoms and in vivo on animals using our laboratory’s Raman point system as reference.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.