Non-rotational multi-channel endoscopic OCT for trajectory-resolved imaging in stereotactic brain biopsy

Optical coherence tomography (OCT) enables high-resolution imaging in compact fiber-optic configurations, making it attractive for minimally invasive applications. We present a non-rotational, multi-channel endoscopic OCT (E-OCT) catheter capable of trajectory-resolved imaging without mechanical scanning. The device integrates four ultrathin side-viewing fiber probes within a biopsy-compatible housing and employs time-division multiplexing for sequential multi-angle acquisition. This architecture provides structural, vascular, and flow contrast from spatially separated regions while maintaining mechanical stability. The system was validated using tissue-mimicking phantoms, ex vivo glioma-bearing rat brains, and an in vivo rabbit glioma model. Experimental results demonstrated consistent multi-slice endoscopic imaging and reliable visualization of tissue microstructure and vascular features from tumor-associated and adjacent non-tumor regions. These proof-of-concept findings from the single in vivo study indicate the feasibility of using multimodal E-OCT imaging to provide complementary structural and vascular information during stereotactic brain biopsy.