Smoke inhalation induced airway injury is the major cause of morbidity and mortality among victims of fires. There is no clinically available imaging technique that is capable of detecting and assessing the degree of injury at early stages. The purpose of this study is to demonstrate feasibility of rapid, high resolution, 3-dimensional swept source optical coherence tomography (3D SSOCT) to detect early airway injury changes following smoke inhalation exposure.
New Zealand white rabbits were anesthetized and mechanically ventilated. Baseline 3D SSOCT images were taken before exposure to cotton smoke, followed by sequential OCT measurements postexposure. The OCT system obtained 3-D helical scanning using a microelectromechanical system motor based endoscope, and a 12mm long section within the trachea was scanned. The swept source OCT system achieved real-time data processing and image displaying at the speed of 20 frames per second. Longitudinal images were reconstructed via an image processing algorithm we developed to remove motion artifacts caused by ventilation and pulse.
Significant thickening of mucosal layer at 2-hour postexposure was observed. Real-time displayed circumferential OCT images showed the distribution of swelling most evident at the posterior margins of the cartilage rings. Images could be reconstructed in any direction, and longitudinal OCT images revealed capabilities for measuring overall mucosal swelling along the longitudinal direction.
This study demonstrates the feasibility of a 3-D MEMS motor based SSOCT endoscope system in detection and assessment of early airway injury induced by smoke inhalation. Further studies investigating quantitative measures of smoke-induced airway thickening using 3D SSOCT will be performed.
The ability to detect and measure early inhalation airway injury using minimally invasive 3D SSOCT may provide a valuable tool for assessing extent of injury, impending airway obstruction, triage and prognosis, as well as a method for accurate assessment of response to therapy.
Jiechen Yin, No Financial Disclosure Information; Product/procedure/technique that is considered research and is NOT yet approved for any purpose. Dr. Zhongping Chen is a co-founder and a Founding Director of OCT Medical Imaging Inc..