Scar formation in tissue is a healing process that inhibits normal tissue function through the deposition of predominantly disorganized type I collagen which is much more rigid than native collagen. Scarring in the vocal fold is especially debilitating as the vocal fold requires flexibility and freedom of movement to produce voicing. Furthermore the vocal fold has a very layered and organized structure with type I collagen in the basement membrane providing organ structural support, while type III collagen is in high concentration in the deep layer of the vocal fold. Using Dynamic Optical Contrast Imaging (DOCI) on unstained histological rabbit vocal fold slides (formalin fixed paraffin embedded tissue, FFPE), we were able to use subtle differences in fluorescence lifetime between native and scarred collagen types to image molecular evolution of scarring following injury. The degree of scarring and the DOCI fluorescence life time shift correlated with molecular and functional evaluations of scarring. Preliminary results demonstrates DOCI could be used as a prognostic tool useful to clinicians by depicting scar damage on vocal folds, (VF) not visible to the unaided eye or with white light endoscopic imaging.
Surgical excision of an adenomatous or hypercellular parathyroid gland is typically the treatment of choice for primary hyperparathyroidism. Intraoperative identification can be challenging due to potential variable location and indistinct features of these glands. In 115 ex-vivo specimens we evaluated the efficacy of DOCI in identifying hypercellular parathyroid glands. Significant imaging differences were seen between hypercellular vs normal parathyroid glands vs other adjacent healthy tissues across 8 spectral channels (p<0.05). Our classification result (100% sensitivity, 98.8% specificity) using a logistic regression classifier further corroborated that DOCI has the capacity to accurately identify and differentiate parathyroid glands from surrounding tissues. DOCI enables sensitive and specific mapping of parathyroid location, leading to improved accuracy of the surgical procedure, reduced time to successful completion, fewer risks and improved patient outcomes.
Due to the anatomic confines of the head and neck, resection of oropharyngeal squamous cell carcinoma (OPSCC) necessitates precise margins that balance oncologic outcomes with preservation of speech and swallowing. Dynamic Optical Contrast Imaging (DOCI) is a novel non-invasive imaging system that measures endogenous fluorescence decay rates. DOCI acquires images in real-time (<2 secs) with an operatively relevant wide field of view (6.5 cm2). After surgical excision, 10 OPSCC specimens were imaged using DOCI. In all 10 specimens, DOCI clearly differentiated healthy tissue from cancer (p<0.01). DOCI has the potential to improve patient oncologic and functional outcomes by allowing the surgeon to precisely determine margins intraoperatively.
As we know, fluorescence lifetime imaging has demonstrated the ability to accurately detect materials and tissue constituents1–3. Current fluorescence lifetime systems rely on accurate temporal sampling to capture the tails of the decaying emission. These data are often fit to an exponential decay model3,4. Although these methodologies are powerful tools but they are often implemented as point measurement systems and require significant postprocessing to compute decay times or coefficients5–8. In some applications these factors can hinder clinical translation. Based on these observations, our group has developed algorithms and built simple, fast, and wide field imaging system9,10. This method uses a gated charge-coupled device (CCD) and a liquid light cable guided LED to compare the decay-time image intensity vs excited state image intensity, thus generating a spatially resolved maps of relative differences in autofluorescence decay of tissue constituents. This approach ensures very fast updating speed (< 2 sec per frame), big field of view (20 mm x 20 mm), excellent depth of field (up to 6 mm) for surface curvature of interested target at reasonable working distance (~50 mm). This innovative imaging system has a temporal resolution of 0.16 nanosecond, spatial resolution of 70 μm and has proved the capability to differentiate visibly similar tissue types, which has been validated with both fluorescent dyes and ex vivo human tissue samples in comparison to commercially available FLIM microscope. This work establishes a foundation to confirm the utility of our upgraded DOCI system for intraoperative tissue differentiating/imaging. Validation with a larger number of samples is currently ongoing.
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.