Korean J Cerebrovasc Surg.  2004 Sep;6(2):165-168.

Magnetic Resonance Imaging of the Ischemic Penumbra: Diffusion-Perfusion Mismatch in Acute Stroke Patients

• Joo JY
• Ahn JY
• Yoon PH
• Kim SH

Abstract

The ischemic penumbra is defined as functionally impaired but salvageable ischemic brain tissue surrounding an irreversibly damaged core. Therefore, rapid and precise identification of the penumbra is of considerable interest for decision-making in acute stroke treatment. The region with perfusion abnormality but no diffusion lesion (the so-called diffusion-perfusion mismatch) identifies tissue that is hypoperfused but that not yet experienced advanced bioenergetic failure and represents the penumbra. Thus, diffusion-perfusion mismatch are predicted to have the most lesion growth and may benefit most from any perfusion-altering therapies. The time window available for salvage of the penumbra in selected patients may be much longer than the traditional, presumed 3- to 6-hour window and that diffusion-perfusion MRI has the ability to identify these patients. Multimodal MRI allows therapeutic decisions to be based on individual patient pathophysiological information, allowing the time window to be extended in appropriate patients.

Keyword

Ischemic penumbra; Magnetic resonance imaging; Diffusion; Perfusion; Stroke

MeSH Terms

Brain
Diffusion
Energy Metabolism
Humans
Magnetic Resonance Imaging*
Perfusion
Stroke*