Segmental airway adenocarcinoma-simulating phantom for endoscopic near-infrared optical coherence tomography.

Significance: There is an unmet need for readily accessible imaging targets to verify whether devices can discriminate lesions from healthy tissue and identify sub-surface vasculature in the small airways.

Aim: Our aim is to develop a phantom that mimics human segmental airway adenocarcinoma in vivo for 1310 nm endoscopic optical coherence tomography (OCT) and angiography characterization.

Approach: We develop phantoms using a mixture of agar, intralipid, and coconut oil cured in a 3D printed mold with embedded tubing to mimic vasculature. The parenchyma optical attenuation coefficient (OAC) is calibrated using optical transmission measurements from an agar and intralipid dilution series. Depth-resolved OAC histogram distributions, analysis of variance, and image quality are used to assess repeatability and biofidelity of these phantoms.

Results: Transmission measurements show large increases in OAC when intralipid is cured with agar compared with water-intralipid dilutions. Representative phantom OACs show repeatability within 2.7% and match normal in vivo tissue measurements within 16%. Embedded lesion phantoms achieve imaging characteristics of in vivo adenocarcinoma. Fluid flow within embedded tubing is visualized with Doppler OCT.

Conclusions: The segmental airway phantoms demonstrate in vivo human imaging characteristics, including structural and optical markers of pathological progression-providing a platform for imaging system characterization and optimization.