PRIMARY OBJECTIVES:
I. To optimize two major parameters of computed tomography (CT) imaging for optimal detection of intracranial metastatic lesions.
Ia. Virtual monochromatic image reconstruction. Ib. Contrast bolus timing. II. To measure the detection accuracy of CT compared to the diagnostic standard of care gadolinium-based "Gamma Knife (GK)" protocol magnetic resonance imaging (MRI).
OUTLINE:
Within 7 days before the standard Gamma Knife MRI, patients undergo DECT scan over 6 seconds at 1.5, 5, 10, and 20 minutes after receiving the contrast agent.
