Skull base pneumatization is anatomically variable and clinically relevant for temporal bone and transsphenoidal surgical corridors, but manual volumetric segmentation is time-consuming. This retrospective pilot study evaluated a clinician-guided deep learning workflow for computed tomography segmentation of temporal bone/mastoid and sphenoid sinus pneumatization. Bone-window computed tomography (CT) datasets were curated, converted to NIfTI format, and segmented using 3D Slicer, MONAI Label, and a three-dimensional SegResNet-based model. The mastoid workflow used side-specific temporal bone crops, while the sphenoid workflow used full-head CT volumes. The final mastoid development dataset included 122 side-cases, with an independent 28 side-case expert-validation cohort. The sphenoid arm included 117 expert-submitted development labels and a separate 17-case expert-validation cohort. The mastoid model achieved strong expert agreement, with mean Dice 0.9691 and median Dice 0.9794 on the independent validation set. The sphenoid workflow achieved a best internal validation Dice of 0.8750, while expert comparison of saved automatic masks showed mean Dice 0.9426 and median Dice 0.9408. Exploratory mask analysis enabled volumetric, densitometric, and extension-pattern assessment of pneumatized skull base compartments. This research supports clinician-guided deep learning as a feasible approach for reproducible CT-based skull base pneumatization segmentation and radiomic analysis.