Bu Ruofei, Price Hillel, Mitran Sorin, Zdanski Carlton, Oldenburg Amy L
Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina, USA, 27599.
Department of Physics and Astronomy, University of North Carolina at Chapel Hill, North Carolina, USA, 27599.
Proc SPIE Int Soc Opt Eng. 2016;9689. doi: 10.1117/12.2213186.
Quantitative endoscopic imaging is at the vanguard of novel techniques in the assessment upper airway obstruction. Anatomic optical coherence tomography (aOCT) has the potential to provide the geometry of the airway lumen with high-resolution and in 4 dimensions. By coupling aOCT with measurements of pressure, optical coherence elastography (OCE) can be performed to characterize airway wall stiffness. This can aid in identifying regions of dynamic collapse as well as informing computational fluid dynamics modeling to aid in surgical decision-making. Toward this end, here we report on an anatomic optical coherence tomography (aOCT) system powered by a wavelength-swept laser source. The system employs a fiber-optic catheter with outer diameter of 0.82 mm deployed via the bore of a commercial, flexible bronchoscope. Helical scans are performed to measure the airway geometry and to quantify the cross-sectional-area (CSA) of the airway. We report on a preliminary validation of aOCT for elastography, in which aOCT-derived CSA was obtained as a function of pressure to estimate airway wall compliance. Experiments performed on a Latex rubber tube resulted in a compliance measurement of 0.68±0.02 mm/cmHO, with R=0.98 over the pressure range from 10 to 40 cmHO. Next, ex vivo porcine trachea was studied, resulting in a measured compliance from 1.06±0.12 to 3.34±0.44 mm/cmHO, (R>0.81). The linearity of the data confirms the elastic nature of the airway. The compliance values are within the same order-of-magnitude as previous measurements of human upper airways, suggesting that this system is capable of assessing airway wall compliance in future human studies.
定量内镜成像处于评估上气道阻塞新技术的前沿。解剖光学相干断层扫描（aOCT）有潜力以高分辨率和四维方式提供气道腔的几何形状。通过将aOCT与压力测量相结合，可以进行光学相干弹性成像（OCE）以表征气道壁硬度。这有助于识别动态塌陷区域，并为计算流体动力学建模提供信息以辅助手术决策。为此，我们在此报告一种由扫频激光源驱动的解剖光学相干断层扫描（aOCT）系统。该系统采用外径为0.82毫米的光纤导管，通过商用柔性支气管镜的通道进行部署。进行螺旋扫描以测量气道几何形状并量化气道的横截面积（CSA）。我们报告了aOCT弹性成像的初步验证，其中获得了aOCT衍生的CSA作为压力的函数，以估计气道壁顺应性。在乳胶橡胶管上进行的实验得出顺应性测量值为0.68±0.02毫米/厘米水柱，在10至40厘米水柱的压力范围内R = 0.98。接下来，对离体猪气管进行了研究，测量得到的顺应性为1.06±0.12至3.34±0.44毫米/厘米水柱，（R> 0.81）。数据的线性证实了气道的弹性性质。顺应性值与先前对人类上气道的测量值处于同一数量级，表明该系统能够在未来的人体研究中评估气道壁顺应性。
