title: Imaging of cardiovascular structures using near-infrared femtosecond multiphoton laser scanning microscopy.
abstract: Multiphoton imaging represents a novel and very promising medical diagnostic technology for the high-resolution analysis of living biological tissues. We performed multiphoton imaging to analyzed structural features of extracellular matrix (ECM) components, e.g., collagen and elastin, of vital pulmonary and aortic heart valves. High-resolution autofluorescence images of collagenous and elastic fibers were demonstrated using multifluorophore, multiphoton excitation at two different wavelengths and optical sectioning, without the requirement of embedding, fixation, or staining. Collagenous structures were selectively imaged by detection of second harmonic generation (SHG). Additionally, routine histology and electron microscopy were integrated to verify the observed results. In comparison with pulmonary tissues, aortic heart valve specimens show very similar matrix formations. The quality of the resulting three-dimensional (3-D) images enabled the differentiation between collagenous and elastic fibers. These experimental results indicate that multiphoton imaging with near-infrared (NIR) femtosecond laser pulses may prove to be a useful tool for the nondestructive monitoring and characterization of cardiovascular structures.
authors.affiliation: Children's Hospital Los Angeles, Saban Research Institute, 4650 Sunset Boulevard, MS#137, Los Angeles, California 90027, USA. b7sckt@web.de
authors.forename: Katja
authors.initials: K
authors.lastname: Schenke-Layland
authors.forename: Iris
authors.initials: I
authors.lastname: Riemann
authors.forename: Ulrich A
authors.initials: UA
authors.lastname: Stock
authors.forename: Karsten
authors.initials: K
authors.lastname: König
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000648:ultrastructure*; D003094:Collagen / Q000648:ultrastructure; D004549:Elastin / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000648:ultrastructure; D007150:Immunohistochemistry / Q000379:methods; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D036641:Microscopy, Fluorescence, Multiphoton; D011664:Pulmonary Valve / Q000648:ultrastructure*; D012756:Sheep; D019265:Spectroscopy, Near-Infrared; D013194:Staining and Labeling
chemical_list: D003094:Collagen; D004549:Elastin