Imaging Evaluation of the Transient Ischemic Attack
A transient ischemic attack is a retrospective diagnosis. It is a neurologic deficit that has completely resolved.
While the signs and symptoms of the neurologic episode are taking place, must be considered as an acute stroke and the imaging strategy is completely different.
The ACR Appropriateness Criteria, Cerebrovascular Disease*, that a transient ischemic attack may appropriately be imaged with:
- MRI of the head without contrast
- MRI of the head without and with contrast
- MRI of the head and neck without contrast
- MRI of the head and neck without and with contrast
- CT of the head without contrast
- CTA of the head and neck with contrast
All of the above have an ACR appropriateness rating of 8.
The ACR rating scale is: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate.
2013 Imaging Recommendations for Acute Stroke and Transient Ischemic Attack Patients** state:
“When acute revascularization therapy is not being considered, the role of imaging is primarily focused on diagnosis, prevention of immediate complications, and the identification of potentially treatable causes of future stroke. In patients with TIAs, multi-
modal MR imaging is preferred, and NCCT should be obtained only if MR imaging is not available, as NCCT has limited utility in patients whose symtoms have resolved. DWI can demonstrate lesions in approximately 40% of TIA patients, and DWI positivity in TIA patients is associated with a higher risk of recurrent ischemic events. The distribution of
carotid disease, and so forth).
“MR-based perfusion imaging, either with dynamic susceptibility contrast or ASL, may additionally identify a vascular etiology in TIA patients.
“CTA or MRA of the intracranial and cervical arteries and duplex sonography (DUS) for the cervical arteries are used to identify stenosis and/or occlusion (level Ib) and determine appropriate secondary prevention, such as extracranial carotid revascularization, for these
patients. An appropriate evaluation of cardiac sources of TIA/stroke (eg, echocardiography) should be performed.”
*Cerebrovascular Disease, American College of Radiology ACR Appropriateness Criteria®. Date of origin: 1996. Last review date: 2011.
**2013 Imaging Recommendations for Acute Stroke and Transient Ischemic Attack Patients: A Joint Statement by the AmericanSociety of Neuroradiology, the American College of Radiology, and the Society of NeuroInterventional Surgery.