Linda Knutsson
Professor
Imaging the physiological evolution of the ischemic penumbra in acute ischemic stroke
Författare
Summary, in English
We review the hemodynamic, metabolic and cellular parameters affected during early ischemia and their changes as a function of approximate cerebral blood flow ( CBF) thresholds. These parameters underlie the current practical definition of an ischemic penumbra, namely metabolically affected but still viable brain tissue. Such tissue is at risk of infarction under continuing conditions of reduced CBF, but can be rescued through timely intervention. This definition will be useful in clinical diagnosis only if imaging techniques exist that can rapidly, and with sufficient accuracy, visualize the existence of a mismatch between such a metabolically affected area and regions that have suffered cell depolarization. Unfortunately, clinical data show that defining the outer boundary of the penumbra based solely on perfusion-related thresholds may not be sufficiently accurate. Also, thresholds for CBF and cerebral blood volume ( CBV) differ for white and gray matter and evolve with time for both inner and outer penumbral boundaries. As such, practical penumbral imaging would involve parameters in which the physiology is immediately displayed in a manner independent of baseline CBF or CBF threshold, namely pH, oxygen extraction fraction ( OEF), diffusion constant and mean transit time ( MTT). Suitable imaging technologies will need to meet this requirement in a 10-20 min exam.
Avdelning/ar
- Medicinsk strålningsfysik, Lund
- MR Physics
Publiceringsår
2018
Språk
Engelska
Sidor
1500-1516
Publikation/Tidskrift/Serie
Journal of Cerebral Blood Flow and Metabolism
Volym
38
Issue
9
Dokumenttyp
Artikel i tidskrift
Förlag
Nature Publishing Group
Ämne
- Radiology, Nuclear Medicine and Medical Imaging
Status
Published
Projekt
- Natural sugar as an MRI contrast agent for cancer diagnosis
- Optimisation and Validation of Dynamic Susceptibility Contrast MRI
Forskningsgrupp
- MR Physics
ISBN/ISSN/Övrigt
- ISSN: 1559-7016