The invention relates to systems and methods for diagnosing strokes. In particular, systems and methods for acquiring timely patient status information are described that enable a physician to make diagnostic and treatment decisions relating to ischemic and hemorrhagic strokes. The systems and methods enable the efficient and quantitative assessment of arterial collaterals within the brain for aiding these decisions in the case of ischemic strokes. In the case of hemorrhagic strokes, the systems and methods are effective in determining if there is a leak and what is the rate of leaking.
