Kaiser Imaging

Initial Brain Imaging for TIA and Stroke (October 1996)

The purpose of this guideline is to establish the role of computed tomography (CT) imaging and to promote its accurate interpretation at all centers in the setting of suspected acute TIA and stroke.

Non-contrast CT is the study of choice in the evaluation of patients with suspected acute TIA or stroke.

Imaging features of early infarction may be subtle. These include loss of normal gray-white differentiation, mass effect such as sulcal effacement, and hypodensity in the ischemic zone.

The presence of SAH on CT obviates the need for lumbar puncture.

CT is highly sensitive in the detection of ICH, which appears as a hyperdense region.

Magnetic Resonance Imaging (MRI):
MRI has a limited role in the initial evaluation of patients with suspected acute TIA or stroke. MRI may yield better diagnostic information in the non-acute setting, where it may obviate the need for CT.


  1. Urgent non-contrast CT scan should be obtained and interpreted by an experienced physician in patients with suspected acute: TIA, ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage. (Expert Opinion: Strong Consensus)
  1. CT should obtained on a STAT basis for a potential t-PA candidate.

(Research Evidence: Grade A)

  1. When considering MRI as the initial brain imaging modality for suspected acute TIA or stroke, discussion with neurology is recommended. (Expert Opinion: Strong Consensus)