Assessing tracheal health using optical metabolic imaging and optical coherence tomography

The health and pathophysiology of the tracheal mucosa is an important yet poorly understood aspect of respiratory medicine. Cilia, hair-like organelles important for mucociliary clearance, line the tracheal mucosa. Ciliary dysfunction leads to severe diseases such as primary ciliary dyskinesia and cystic fibrosis. Optical imaging can monitor ciliary function in vivo, ex vivo, and in vitro to understand the genesis of ciliary disease and potential treatment targets. Specifically, optical coherence tomography (OCT) has been used to quantify multiple parameters of ciliary motility in 2D and 3D. However, OCT inherently lacks information about the biochemical or metabolic state of cells. Optical metabolic imaging (OMI) quantitatively assesses cellular metabolism by imaging the autofluorescence intensities of endogenous metabolic co-enzymes nicotinamide dinucleotide (NADH) and flavin adenine dinucleotide (FAD). OMI probes the optical redox ratio (NADH intensity divided by FAD intensity), which is sensitive to the relative amounts of electron donors and acceptors within a cell. Ciliary function is highly dependent on ATP and therefore tightly linked to NADH and FAD levels through multiple metabolic pathways Please click Additional Files below to see the full abstract