Department of Neurology, Oita University Faculty of Medicine, Oita, Japan.
J Stroke Cerebrovasc Dis. 2014 May-Jun;23(5):795-8. doi: 10.1016/j.jstrokecerebrovasdis.2013.10.003. Epub 2013 Nov 13.
Various imaging modalities are used to identify the ischemic penumbra in patients with acute ischemic stroke. Although single-photon emission computed tomography (CT), perfusion-weighted magnetic resonance imaging (MRI), and perfusion CT are used to evaluate residual cerebral blood flow in the ischemic area, validation of the perfusion threshold for the penumbra has not been established. The ischemic core corresponds generally to areas with early ischemic changes, such as parenchymal hypoattenuation on CT, restricted apparent diffusion coefficient on diffusion-weighted MRI, or very low cerebral blood volume on perfusion CT. A mismatch of these abnormalities is thought to correspond to the ischemic penumbra and has been used in clinical trials. Although new ligands, such as (18)F-fluoromisonidazole, that bind to hypoxic but viable ischemic tissue are currently available, positron emission tomography has yet to be developed as a clinical tool.
各种成像方式被用于识别急性缺血性脑卒中患者的缺血半暗带。虽然单光子发射计算机断层扫描（CT）、灌注加权磁共振成像（MRI）和灌注 CT 被用于评估缺血区域的脑血流残留，但尚未确定半暗带的灌注阈值。缺血核心通常对应于早期缺血改变的区域，例如 CT 上的实质低衰减、弥散加权 MRI 上的受限表观弥散系数或灌注 CT 上的极低脑血容量。这些异常的不匹配被认为对应于缺血半暗带，并已在临床试验中应用。尽管目前有（18）F-氟米索硝唑等新配体可与缺氧但存活的缺血组织结合，但正电子发射断层扫描尚未开发成为临床工具。
