Dual modality instrument for simultaneous optical coherence tomography imaging and fluorescence spectroscopy

Abstract

We develop a dual-modality device that combines the anatomical imaging capabilities of optical coherence tomography (OCT) with the functional capabilities of laser-induced fluorescence (LIF) spectroscopy. OCT provides cross-sectional images of tissue structure to a depth of up to 2 mm with approximately 10-microm resolution. LIF spectroscopy provides histochemical information in the form of emission spectra from a given tissue location. The OCT subsystem utilizes a superluminescent diode with a center wavelength of 1300 nm, whereas a helium cadmium laser provides the LIF excitation source at wavelengths of 325 and 442 nm. Preliminary data are obtained on eight postmortem aorta samples, each 10 mm in length. OCT images and LIF spectra give complementary information from normal and atherosclerotic portions of aorta wall. OCT images show structures such as intima, media, internal elastic lamina, and fibrotic regions. Emission spectra ratios of 520/490 (325-nm excitation) and 595/635 (442-nm excitation) could be used to identify normal and plaque regions with 97 and 91% correct classification rates, respectively. With miniaturization of the delivery probe and improvements in system speed, this dual-modality device could provide a valuable tool for identification and characterization of atherosclerotic plaques.

Three‐dimensional multiphoton/optical coherence tomography for diagnostic applications in dermatology

“…A MPT/confocal laser scanning microscopy system was used to investigate various dermatological diseases such as actinic keratosis and stucco keratosis [51]. Similarly, clinical trials using OCT in combination with imaging techniques such as Raman spectroscopy, coherent anti-Stokes Raman spectroscopy, photoacoustic tomography and fluorescence spectroscopy has been demonstrated and these multimodal systems were able to provide complimentary structural and functional information [52][53][54][55]. Recently, a multimodal optical microscope incorporating OCM, MPT and FLIM have been designed and developed to obtain images of human skin in vivo [56].…”

Integrated structural and functional optical imaging combining spectral-domain optical coherence and multiphoton microscopy

“…Recently, an alternative approach has been proposed that consists of combining different optical imaging techniques to provide different yet complementary information [4][5][6]. Multiphoton microscopy (MPM) has been shown to be a highly advantageous approach for biological imaging since its first exploitation [7].…”

Optical coherence tomography – near infrared spectroscopy system and catheter for intravascular imaging

“…Furthermore, fluorescence imaging has been demonstrated as a complementary modality for OCT to provide additional information about molecular signatures [28][29][30][31][32][33]. Endogenous fluorescence imaging based on laser-induced fluorescence spectroscopy can also complement OCT and provide molecular information non-invasively [32,33]. Nonetheless, exogenous fluorescence imaging requires perturbative chemical labeling of coronary tissue.…”