Supplementary Material for: Aneurysm Architecture: First in vivo Imaging of Human Cerebral Aneurysms with Extravascular Optical Coherence Tomography

<b><i>Objective:</i></b> The present study was conducted to explore the value of 3-dimensional microscope integrated extravascular optical coherence tomography (OCT) as the first suitable intraoperative imaging modality of cerebral aneurysm (CA) and parent vessel wall morphology. <b><i>Methods:</i></b> Incidental CAs (<i>n</i> = 16) of the anterior circulation with indication for microsurgical clipping were scanned. <b><i>Results:</i></b> Analysis revealed that intraoperative OCT achieved to delineate the microstructural composition of the parent vessel in all cases and the CA wall in 68.8%. Clinical relevant characteristics such as thickness, calcification, residual tunica media, and atherosclerotic plaque of CA wall could be demonstrated with high image quality approaching the spatial resolution of histopathology. <b><i>Conclusion:</i></b> Our findings demonstrate that intraoperative OCT may hold promise as an additional imaging tool during neurovascular procedures.