title: Static and dynamic imaging of alveoli using optical coherence tomography needle probes.
abstract: Imaging of alveoli in situ has for the most part been infeasible due to the high resolution required to discern individual alveoli and limited access to alveoli beneath the lung surface. In this study, we present a novel technique to image alveoli using optical coherence tomography (OCT). We propose the use of OCT needle probes, where the distal imaging probe has been miniaturized and encased within a hypodermic needle (as small as 30-gauge, outer diameter 310 μm), allowing insertion deep within the lung tissue with minimal tissue distortion. Such probes enable imaging at a resolution of ∼12 μm within a three-dimensional cylindrical field of view with diameter ∼1.5 mm centered on the needle tip. The imaging technique is demonstrated on excised lungs from three different species: adult rats, fetal sheep, and adult pigs. OCT needle probes were used to image alveoli, small bronchioles, and blood vessels, and results were matched to histological sections. We also present the first dynamic OCT images acquired with an OCT needle probe, allowing tracking of individual alveoli during simulated cyclical lung inflation and deflation.
authors: Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, University of Western Australia, Crawley, Western Australia, Australia. robert.mclaughlin@uwa.edu.au
authors: Robert A
authors: RA
authors: McLaughlin
authors: Xiaojie
authors: X
authors: Yang
authors: Bryden C
authors: BC
authors: Quirk
authors: Dirk
authors: D
authors: Lorenser
authors: Rodney W
authors: RW
authors: Kirk
authors: Peter B
authors: PB
authors: Noble
authors: David D
authors: DD
authors: Sampson
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000033:anatomy & histology; D055745:Bronchioles / Q000033:anatomy & histology; D004867:Equipment Design; D006652:Histological Techniques; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008904:Miniaturization; D009339:Needles; D011650:Pulmonary Alveoli / Q000033:anatomy & histology* / Q000098:blood supply / Q000196:embryology; D051381:Rats; D017208:Rats, Wistar; D012756:Sheep; D013552:Swine; D041623:Tomography, Optical Coherence / Q000295:instrumentation*