Diagnosis of peripheral lung nodules is challenging because they are rarely visualized endobronchially. Imaging
techniques such as endobronchial ultrasound (EBUS) are employed to improve tumor localization. The current EBUS
probe provides limited nodule characterization and has an outer diameter of 1.4 mm that restricts access to small
peripheral airways. We report a novel co-registered autofluoresence Doppler optical coherence tomography (AF/DOCT)
system with a 0.9 mm diameter probe to characterize peripheral lung nodules prior to biopsy in vivo.
Method: Patients referred for evaluation of peripheral lung nodules underwent bronchoscopy with examination of
standard EBUS and the novel AF/DOCT system. The lesion of interest was first identified with EBUS and then imaged
with the AF/DOCT system. The abnormal area was biopsied. AF/DOCT images of pathology proved lung malignancies
were reviewed by a panel of a pathologist, respirologists, and AF/DOCT experts.
Results: Eleven patients with biopsy proven lung cancer underwent examination with AF/DOCT. The majority of the
cancers were adenocarcinoma. AF/DOCT images were obtained in all patients. There were no complications to the
procedures. Lung abnormalities visualized in AF/ OCT images were observed in 11 cases. In one case large blood
vessels were identified and biopsy was avoided.
Conclusion: In this pilot study, AF/DOCT obtained high quality images of peripheral pulmonary nodules. The present
study supports the safety and feasibility of AF/DOCT for the evaluation of lung cancer. The addition of Doppler
information may improve biopsy site selection and reduce hemorrhage.
Although there are more women than men dying of chronic obstructive pulmonary disease (COPD) in the United States and elsewhere, we still do not have a clear understanding of the differences in the pathophysiology of airflow obstruction between the sexes. Optical coherence tomography (OCT) is an emerging imaging technology that has the capability of imaging small bronchioles with resolution approaching histology. Therefore, our objective was to compare OCT-derived airway wall measurements between males and females matched for lung size and in anatomically matched small airways. Subjects 50-80 yrs were enrolled in the British Columbia Lung Health Study and underwent OCT and spirometry. OCT was performed using a 1.5mm diameter probe/sheath in anatomically matched airways for males and females; the right lower lobe (RB8 or RB9) or left lower lobe (LB8 or LB9) during end-expiration. OCT airway wall area (Aaw) was obtained by manual segmentation. For males and females there was no significant difference in OCT Aaw (p=0.12). Spearman correlation coefficients indicated that the forced expiratory volume in 1 second (FEV1) and Aaw were significantly correlated for males (r=-0.78, p=0.004) but not for females (r=-0.20, p=0.49) matched for lung size. These novel OCT findings demonstrate that while there were no overall sex differences in airway wall thickness, the relationship between lung function and airway wall thickness was correlated only in men. Therefore, factors other than airway remodeling may be driving COPD pathogenesis in women and OCT may provide important information for investigating airway remodeling and its relationship with COPD progression.