The purpose of this study is to provide an illustrated review of the most common craniotomy approaches used by modern neurosurgeons.

Inclusion Criteria: any patient undergoing craniotomy at UF Health Jacksonville during this time frame who have a pre- and post- MRI/CT from craniotomy.

Obtain records: We will obtain this information via a retrospective chart review between July 1, 2014 and July 1, 2019 on mPower, a software database offered by UF Health Jacksonville of radiology studies and reports.

Data coding and data analysis: One subject will be chosen for each type, without prior knowledge of identifiable information. That subject's MRN will be used to identify images from before and after the procedure. One de-identified image will be pulled from PACS for pre-procedure, and another one post-procedure. No dates will remain on either image. The same will be done for each of the 15 craniotomy types: 2 images per patient, one pre- and one post-procedure. Identifiable information will be anonymized on a spreadsheet by using a code that will be discarded after the chart review concludes.