Noncontrast conventional computed tomography in the evaluation of acute stroke.

The advantages of CT scanning in the assessment of hyperacute stroke patients include convenience, accuracy, speed, and low cost. CT scanning is presently considered to be the standard of care for the detection of acute extra-axial and parenchymal hemorrhage, although newer MRI techniques are challenging this claim. The accuracy of CT scanning for stroke detection can be optimized by the use of appropriate scanning technique, as well as interactive image review at a picture archiving and communication system workstation using narrow window and level settings. More importantly, CT scanning has prognostic value for patients receiving thrombolytic treatment by helping to predict both responses to treatment and hemorrhage risk. Finally, as will be discussed in other articles in this issue, CT angiography can be performed in the same imaging session as noncontrast CT scanning without substantially increasing the time required for patient evaluation. This provides data regarding vascular patency and tissue perfusion, which are valuable in the triage of stroke patients.