Which imaging modality offers a perfusion map and helps determine salvageable brain tissue in acute stroke?

Which imaging modality offers a perfusion map and helps determine salvageable brain tissue in acute stroke?

• A. CT Angiography
• B. MR Perfusion
• C. T1 Weighted MRI
• D. Duplex Ultrasonography

Answer: (B)

Perfusion imaging is about showing how blood reaches brain tissue, which is crucial for spotting tissue that is at risk but still salvageable in an acute stroke. The idea is to look for a mismatch: tissue that has reduced blood flow but has not yet developed irreversible damage. MR perfusion provides maps of parameters like cerebral blood flow, cerebral blood volume, and mean transit time (and Tmax), allowing you to visualize which areas are underperfused while diffusion imaging shows where cell death has already occurred. When these two images are considered together, you can identify the penumbra—the tissue that may be saved with reperfusion therapy. That combination is what makes MR perfusion particularly useful for determining salvageable brain tissue. Other options either focus on anatomy or vessel status and do not offer the perfusion maps needed to assess tissue viability in the same way.

Perfusion imaging is about showing how blood reaches brain tissue, which is crucial for spotting tissue that is at risk but still salvageable in an acute stroke. The idea is to look for a mismatch: tissue that has reduced blood flow but has not yet developed irreversible damage. MR perfusion provides maps of parameters like cerebral blood flow, cerebral blood volume, and mean transit time (and Tmax), allowing you to visualize which areas are underperfused while diffusion imaging shows where cell death has already occurred. When these two images are considered together, you can identify the penumbra—the tissue that may be saved with reperfusion therapy. That combination is what makes MR perfusion particularly useful for determining salvageable brain tissue. Other options either focus on anatomy or vessel status and do not offer the perfusion maps needed to assess tissue viability in the same way.