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  • Print publication year: 2013
  • Online publication date: May 2013

8 - MR perfusion imaging in neurovascular disease

from Section 2 - Clinical applications


Introduction: Clinical background: what are the diagnostic issues?

A wide variety of vascular diseases can affect the central nervous system. These include acute ischemic stroke, the third most common cause of death in the developed world. The key diagnostic question for acute stroke patients is to determine whether they will benefit from therapies aimed at vessel recanalization and tissue reperfusion [1]. Intravenous (IV) tissue plasminogen activator (tPA) is the only US Food and Drug Administration (FDA)-approved treatment for acute stroke, but must be administered within the 3–4.5-hr time period. However, most stroke victims miss this window or do not have a clearly defined time of onset. In this large group of patients, the presence of a significant mismatch between the volume of under-perfused but not yet infarcted tissue identified by MR imaging may identify patients who may still benefit from tPA [2, 3]. This so-called “diffusion-perfusion mismatch” approach is the dominant paradigm for stroke imaging. Of paramount importance for acute stroke triage is a short MR protocol and near-immediate post-processing such that information regarding large vessel status, ischemic damage, and tissue perfusion is available within minutes [4].

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