BackgroundStereoelectroencephalography (SEEG) is a procedure used to localize the epileptogenic zone in patients with medically refractory epilepsy, involving the stereotactic implantation of electrodes into brain parenchyma. Magnetic Resonance Imaging (MRI), Digital Subtraction Angiography, and Computed Tomography have been used preoperatively to prevent Intracranial Hemorrhage (ICH) by identifying electrode-vessel conflicts (EVC’s) on planned electrode trajectories. There is variation in the use of Digital Subtraction Angiography and non-invasive sequences for vascular planning. Digital Subtraction Angiography provides high spatial resolution, but carries risks of arterial dissection, groin and retroperitoneal hematoma, and a 0.5–1.9% risk of stroke. Our group has incorporated Intravenous Cone Beam Computed Tomography (CBCT A/V) Brain into our SEEG workflow, given its effective implementation in other neurosurgical domains. Primary aims include validating the safety of our CBCT A/V sequence for SEEG planning and determining if CBCT A/V is comparable to other modalities in detecting EVC’s. Secondary aims include elucidating the relationship of conflicting vessel calibre with ICH incidence in SEEG using CBCT A/V imaging. MethodsA single-center retrospective study was conducted of 20 patients who underwent preoperative CBCT A/V Brain and MRI Brain with gadolinium enhancement, encompassing 273 electrode implantations from August 2020 − July 2023. The incidence and grade of post-implant, post-explant symptomatic ICH and asymptomatic ICH was noted. The total number of EVC’s identifiable on MRI and CBCT A/V was recorded, along with average diameter of conflicting vessels. ResultsAcross 20 patients and 273 implanted electrodes, there were four ICH events, where two were symptomatic and two were asymptomatic. The mean diameter of EVC’s across all patients was 1.4 mm (±0.5). A significant difference (P < 0.0001) was observed between the number of EVC’s that CBCT A/V could identify (20) compared to MRI (6). Two EVC’s were identified in the region of two symptomatic ICH’s, with the mean diameter of these conflicted vessels being 1.5 mm (±0.4). The two symptomatic ICH-associated EVC’s were observed on CBCT A/V but not MRI. ConclusionsIn our series, CBCT A/V demonstrates an acceptable safety profile for SEEG planning compared to other imaging modalities. CBCT A/V identified significantly more EVC’s compared to MRI, including those contributing to transient symptomatic intracranial hemorrhage. A conflicting vessel calibre of less than 1.2 mm on CBCT A/V did not contribute to ICH in our SEEG series. Unstructured abstract:For patients with medically refractory epilepsy, stereoelectroencephalography (SEEG) is a procedure utilized to localize the epileptogenic zone by the stereotactic implantation of electrodes into brain parenchyma. Digital Subtraction Angiography and non-invasive neuroimaging sequences have been used preoperatively to identify potential electrode-vessel conflicts (EVC’s) on planned electrode trajectories and prevent ICH. Intravenous Cone Beam Computed Tomography (CBCT A/V) is a sequence that we adopted for SEEG planning at our institution. It provides clear vascular segmentation of both cerebral arteries and veins, potentially reducing ICH risk, without some of the traditional risks associated with Digital Subtraction Angiography. The primary aims included determining if CBCT A/V is comparable to other modalities in detecting EVC’s and validating the safety of our CBCT A/V sequence for SEEG planning. Secondary aims included elucidating the relationship of conflicting vessel calibre with ICH incidence for SEEG. In our SEEG series, we identified two asymptomatic ICH’s, and two symptomatic ICH events, which were transient in nature and recovering within 24 h of onset. CBCT A/V demonstrates an acceptable safety profile, produces a sharp image for visualising vessel contours during SEEG planning, and identifies more clinically significant EVC’s compared to MRI. Conflicting vessels of less than 1.2 mm on CBCT A/V did not contribute to ICH in our SEEG series.