Imaging The Acute Stroke

The role of imaging is increasingly critical in the evaluation of acute stroke. The head CT without contrast remains the most important initial examination, primarily for the detection of intracranial hemorrhage, but also as a screening tool to look for conditions that may mimic stroke clinically, such as neoplasm. CT can also potentially reveal an arterial occlusion immediately (as a hyperdense area), and can provide information about the severity of an ischemic event. In the early hours of an acute stroke, however, the CT scan is often normal, or it can signifi cantly underestimate the severity of the ischemia (Figure 1).