A method and apparatus for evaluating acute stroke patients and for
determining whether a stroke patient will benefit from the use of
thrombolysis therapy includes obtaining measurements of the cerebral
blood flow and cerebral blood volume of the brain of a stroke patient,
determining ischemic areas of the brain where the ischemic areas comprise
the measurements of cerebral blood flow which are less than a first value
and creating a penumbra-infarct map of the ischemic areas of the brain
using the measurements. The infarct area corresponds to the area of the
brain where cerebral blood volume is less than a second value. The
penumbra area corresponds to the area of the brain where cerebral blood
volume is greater than this second dvalue. The method also includes
determining a ratio of penumbra size to the total of penumbra size and
infarct size. When the ratio is greater than a predetermined value, the
stroke patient is a candidate for thrombolysis therapy.