This is a prospective pilot study evaluating the efficacy of DynaCT in direct comparison to conventional catheter angiography in demonstrating the anatomic details of the vessels supplying brain lesions. Forty patients will be recruited for this pilot study.

There are common intracranial lesions that have increased vascularity that makes surgical resection difficult. Embolization can improve the surgical procedure by easing the resection, decreasing blood loss during surgical resection, and improving visibility of the surgical bed during resection. Conventional intra-arterial (IA) angiography is the gold standard to evaluating pathologies for embolization candidates, however the invasiveness of the procedure (with associated risks), time requirements, and resource utilization of evaluating and possibly embolization of these patients are precluding its widespread use.

Devising a test methodology that is quick, with less risk, and can accurately detect arteries that are of value in embolizing these pathologies will improve the utilization as a screening tool and will result in improved resource utilization that focuses only on those patients that require embolization. Lastly, by correlating the Dyna CBV to surgical resection quality (ease of resection, blood loss from surgical site), a non-invasive, controlled method to evaluating embolization quality can be established to aid surgeons in pre-operative planning as well as serve as a method of evaluating embolization materials designed for the blood vessels associated with brain lesions.

The DynaCT technique is a fully FDA-approved application of the Siemens imaging system and software. DynaCT is often performed during our angiographic and interventional procedures. Neurointerventionists have begun to apply this technology within their practices, and the investigators have selectively applied DynaCT for various clinical applications. However, at this point the investigators have not incorporated the technology into clinical care for patients with intracranial lesions.

Although DynaCT is an approved technology, there have been recent improvements in the software performing the 3D reconstruction. These new features will be used in this study and thus the investigators consider them to be "research scans."

Study patients will provide informed consent for the scan and the patients will not be billed for the DynaCT portion of the procedure (only the standard of care conventional angiography). The investigators have specifically chosen to image patients already undergoing conventional angiography for surgical resection in order to have a direct comparison.

Inclusion Criteria:

1. Patients scheduled to have an intracranial lesion evaluated for possible surgical resection.

Exclusion Criteria:

1. Patients with severe contrast allergies
2. Women who are pregnant or lactating.