Identification of major ischemic change. Diffusion-weighted imaging versus computed tomography

Area of Science:

• Neuroradiology
• Stroke Imaging
• Acute Ischemic Stroke

Background:

• Thrombolytic therapy is contraindicated in major infarction cases, defined by CT criteria involving >33% of the middle cerebral artery (MCA) territory.
• Diffusion-weighted imaging (DWI) offers higher sensitivity than CT for acute ischemia detection.
• Advanced MRI techniques like DWI, perfusion imaging, and angiography provide comprehensive data in a single session.

Purpose of the Study:

• To evaluate if DWI can accurately identify the presence and extent of major ischemia in hyperacute stroke patients, comparable to CT.
• To assess the sensitivity of DWI versus CT in detecting acute ischemic changes.

Main Methods:

• Seventeen patients with suspected hemispheric stroke underwent both CT and DWI within 6 hours of symptom onset.
• Neuroradiologists blinded to the results assessed scans for ischemic changes and edema, categorizing them by MCA territory involvement (<33% or >33%).
• Final stroke diagnosis was confirmed using clinical criteria and T2-weighted imaging at 90 days.

Main Results:

• DWI demonstrated 100% sensitivity in detecting acute ischemic changes in 16 of 17 stroke patients, compared to CT's 75% sensitivity.
• DWI accurately identified all 6 patients with major ischemia as defined by CT criteria, showing excellent agreement (kappa=0.88).
• One patient meeting CT criteria for thrombolysis eligibility was found to have major ischemia on DWI.

Conclusions:

• DWI is more sensitive than CT for identifying acute ischemia in stroke patients.
• DWI facilitates easier visualization and assessment of major ischemic regions compared to CT.