FAQs
What MRI sequence detects ischemic stroke earliest?
Diffusion-weighted imaging (DWI) detects ischemic stroke within minutes of arterial blockage, showing bright signals due to cytotoxic edema before other sequences or CT.
How do MRI findings differentiate ischemic from hemorrhagic stroke?
Ischemic stroke shows bright DWI with dark ADC and no blooming on GRE/SWI. Hemorrhage appears as dark blooming on GRE/SWI due to magnetic susceptibility.
What does a DWI-FLAIR mismatch indicate in ischemic stroke?
A bright DWI with normal FLAIR suggests hyperacute ischemic stroke within 6 hours, useful for identifying patients eligible for early thrombolysis.
Why can ADC values 'pseudonormalize' in subacute stroke?
After about 24 hours, ADC values may return near normal despite persistent injury, so combining ADC with DWI and FLAIR is essential to avoid misinterpretation.
How does MRI guide treatment decisions in ischemic stroke?
MRI evaluates lesion size and penumbra via DWI, PWI, and MRA imaging to determine eligibility for IV thrombolysis and mechanical thrombectomy, improving outcomes.
