Tissue-Negative Transient Ischemic Attack: Is There a Role for Perfusion MRI?

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Many transient ischemic attack (TIA) patients lack diffusion-weighted imaging (DWI) evidence of ischemia.
• Accurate diagnosis is crucial for appropriate patient management and stroke prevention.

Purpose of the Study:

• To evaluate the diagnostic utility of perfusion MRI in TIA patients with normal DWI findings.
• To identify perfusion abnormalities using Tmax and cerebral blood flow (CBF) maps.

Main Methods:

• Retrospective analysis of 52 TIA patients with normal DWI and perfusion MRI within 48 hours of symptom onset.
• Independent evaluation of Tmax and CBF maps by two observers.
• Multivariate analysis of perfusion findings, clinical variables, and ABCD2 scores.

Main Results:

• Regional perfusion abnormalities were detected in 23% of patients (12/52).
• Hypoperfused lesions were primarily identified on Tmax maps, while hyperperfusion was seen on CBF maps.
• Perfusion deficits correlated with initial neurological deficits in 92% of affected patients.

Conclusions:

• Perfusion MRI, incorporating Tmax and CBF maps, provides significant diagnostic value in TIA cases with normal DWI.
• It detects delayed perfusion or post-ischemic hyperperfusion in approximately 25% of these patients.