OBJECTIVES-We present the first clinical imaging of human coronary arteries in vivo using a multimodality OCT and near-infrared autofluorescence (NIRAF) intravascular imaging system and catheter.BACKGROUND-While intravascular OCT is capable of providing microstructural images of coronary atherosclerotic lesions, it is limited in its capability to ascertain compositional/molecular features of plaque, including the definitive presence of a necrotic core. A recent study in cadaver coronary plaque has shown that endogenous NIRAF is elevated in necrotic core lesions. The combination of these two technologies in one device may therefore provide synergistic data to aid in the diagnosis of coronary pathology in vivo.

Owing to its superior resolution, intravascular optical coherence tomography (IVOCT) is a promising tool for imaging the microstructure of coronary artery walls. However, IVOCT does not identify chemicals and molecules in the tissue, which is required for a more complete understanding and accurate diagnosis of coronary disease. Here we present a dual-modality imaging system and catheter that uniquely combines IVOCT with diffuse near-infrared spectroscopy (NIRS) in a single dualmodality imaging device for simultaneous acquisition of microstructural and compositional information. As a proof-of-concept demonstration, the device has been used to visualize co-incident microstructural and spectroscopic information obtained from a diseased cadaver human coronary artery. Swanson, "Optical biopsy and imaging using optical coherence tomography," Nat. Med. 1(9), 970-972 (1995). 3. J. G. Fujimoto, "Optical coherence tomography for ultrahigh resolution in vivo imaging," Nat. Biotechnol. 1361-1367 (2003). 4. R. Leitgeb, C. K. Hitzenberger, and A. F. Fercher, "Performance of Fourier domain vs. time domain optical coherence tomography," Opt. Express 11(8), 889-894 (2003). 5. K. Goda, A. Fard, O. Malik, G. Fu, A. Quach, and B. Jalali, "High-throughput optical coherence tomography at 800 nm," Opt. Express 20(18), 19612-19617 (2012 A. Bartlett, M. Rosenberg, and B. E. Bouma, "Three-dimensional coronary artery microscopy by intracoronary optical frequency domain imaging," JACC Cardiovasc. Imaging 1(6), 752-761 (2008). 10. S. Waxman, M. I. Freilich, M. J. Suter, M. Shishkov, S. Bilazarian, R. Virmani, B. E. Bouma, and G. J. Tearney, "A case of lipid core plaque progression and rupture at the edge of a coronary stent: elucidating the mechanisms of drug-eluting stent failure," Circ. Cardiovasc. Interv. 3(2), 193-196 (2010 Opt. Soc. Am. A 4(3), 423-432 (1987 21(11),

Spectrally encoded confocal microscopy (SECM) is a reflectance confocal microscopy technology that uses a diffraction grating to illuminate different locations on the sample with distinct wavelengths. SECM can obtain line images without any beam scanning devices, which opens up the possibility of high-speed imaging with relatively simple probe optics. This feature makes SECM a promising technology for rapid endoscopic imaging of internal organs, such as the esophagus, at microscopic resolution. SECM imaging of the esophagus has been previously demonstrated at relatively low line rates (5 kHz). In this paper, we demonstrate SECM imaging of large regions of esophageal tissues at a high line imaging rate of 100 kHz. The SECM system comprises a wavelength-swept source with a fast sweep rate (100 kHz), high output power (80 mW), and a detector unit with a large bandwidth (100 MHz). The sensitivity of the 100-kHz SECM system was measured to be 60 dB and the transverse resolution was 1.6 µm. Excised swine and human esophageal tissues were imaged with the 100-kHz SECM system at a rate of 6.6 mm 2 /sec. Architectural and cellular features of esophageal tissues could be clearly visualized in the SECM images, including papillae, glands, and nuclei. These results demonstrate that largearea SECM imaging of esophageal tissues can be successfully conducted at a high line imaging rate of 100 kHz, which will enable whole-organ SECM imaging in vivo.