It is extremely vital that we differentiate brain hemorrhage (bleeding) from brain infarcts, when patients present with clinical features of stroke. This is because patients with infarcts are eligible to receive thrombolytic treatment, to lyse the blood clots. On the other hand, thrombolytic treatment is contraindicated in patients with brain hemorrhage (bleed). Drugs used for thrombolytic treatment, if administered to a patient with brain hemorrhage, could prove disastrous, as the hematoma can expand in size, and can prove fatal.
On a CT scan, it is easy to distinguish bleed from an infarct. Infarct is hypodense (black) and bleed is hyperdense (white) on CT scan.
On an MRI, it can get confusing. Both bleed and infarct can appear hyperintense (white) on DWI and FLAIR MRI images, as seen in the first MRI here. To sort out the diagnosis, GRE (SWI) sequences of MRI should be obtained. On SWI (GRE) sequences of MRI, there is suppression of signals in the area of bleed and it appears hypointense (black) as seen in the second MRI image here.