Diffusion-weighted MRI in evaluation of transient ischemic attack

Area of Science:

• Neurology
• Radiology
• Vascular Medicine

Background:

• Diffusion-weighted imaging (DWI) is crucial for identifying acute ischemic lesions in transient ischemic attacks (TIAs).
• However, the clinical significance and interpretation of DWI findings in TIA patients remain debated.
• Understanding the underlying pathophysiology of DWI abnormalities is essential for accurate diagnosis and management.

Purpose of the Study:

• To investigate the prevalence and characteristics of DWI abnormalities in patients experiencing recent TIAs.
• To correlate DWI findings with clinical manifestations and vascular lesion types.
• To determine the utility of DWI in conjunction with magnetic resonance angiography (MRA) for diagnosing TIA subtypes.

Main Methods:

• Analysis of 45 consecutive TIA patients undergoing DWI within 10 days of symptom onset.
• Classification of clinical symptoms based on the Oxfordshire Community Stroke Study criteria (lacunar vs. non-lacunar syndromes).
• Categorization of DWI abnormalities into small-vessel and large-vessel lesions based on vascular distribution; correlation with intracranial MRA findings.

Main Results:

• DWI abnormalities were detected in 14 (31%) of 45 TIA patients.
• DWI-positive patients were significantly more likely to have intracranial occlusive vascular lesions (50%) compared to DWI-negative patients (16%).
• Classical lacunar syndromes were associated with small-vessel lesions in DWI-positive patients, while non-lacunar symptoms correlated with large-vessel lesions.

Conclusions:

• DWI abnormalities, though present in only a third of TIA patients, are strongly associated with intracranial vascular occlusive disease.
• Combining DWI with MRA enhances the detection of large-artery lesions, particularly in patients presenting with lacunar syndromes.
• These findings underscore the importance of DWI in evaluating TIA pathophysiology and guiding treatment strategies.