title: Contrast-enhanced optical coherence tomography with picomolar sensitivity for functional in vivo imaging.
abstract: Optical Coherence Tomography (OCT) enables real-time imaging of living tissues at cell-scale resolution over millimeters in three dimensions. Despite these advantages, functional biological studies with OCT have been limited by a lack of exogenous contrast agents that can be distinguished from tissue. Here we report an approach to functional OCT imaging that implements custom algorithms to spectrally identify unique contrast agents: large gold nanorods (LGNRs). LGNRs exhibit 110-fold greater spectral signal per particle than conventional GNRs, which enables detection of individual LGNRs in water and concentrations as low as 250 pM in the circulation of living mice. This translates to ~40 particles per imaging voxel in vivo. Unlike previous implementations of OCT spectral detection, the methods described herein adaptively compensate for depth and processing artifacts on a per sample basis. Collectively, these methods enable high-quality noninvasive contrast-enhanced imaging of OCT in living subjects, including detection of tumor microvasculature at twice the depth achievable with conventional OCT. Additionally, multiplexed detection of spectrally-distinct LGNRs was demonstrated to observe discrete patterns of lymphatic drainage and identify individual lymphangions and lymphatic valve functional states. These capabilities provide a powerful platform for molecular imaging and characterization of tissue noninvasively at cellular resolution, called MOZART.
authors.affiliation: Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Departments of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.
authors.forename: Orly
authors.initials: O
authors.lastname: Liba
authors.affiliation: Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Departments of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.
authors.forename: Elliott D
authors.initials: ED
authors.lastname: SoRelle
authors.affiliation: Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Departments of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.
authors.forename: Debasish
authors.initials: D
authors.lastname: Sen
authors.affiliation: Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Departments of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.|Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: de la Zerda
mesh_terms: D000465:Algorithms; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D003952:Diagnostic Imaging / Q000379:methods*; D006046:Gold / Q000008:administration & dosage / Q000737:chemistry; D051379:Mice; D043942:Nanotubes / Q000032:analysis; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D003287:Contrast Media; D006046:Gold