Pollock J M, Whitlow C T, Deibler A R, Tan H, Burdette J H, Kraft R A, Maldjian J A
Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
AJNR Am J Neuroradiol. 2008 Aug;29(7):1302-7. doi: 10.3174/ajnr.A1095. Epub 2008 May 1.
Anoxic brain injury is a devastating result of prolonged hypoxia. The goal of this study was to use arterial spin-labeling (ASL) to characterize the perfusion patterns encountered after anoxic injury to the brain.
Sixteen patients with a history of anoxic or hypoxic-ischemic injury ranging in age from 1.5 to 78.0 years (mean, 50.3 years) were analyzed with conventional MR imaging and pulsed ASL 1.0-13.0 days (mean, 4.6 days) after anoxic insult. The cerebral perfusion in each case was quantified by using pulsed ASL as part of the standard stroke protocol. Correlation was made among perfusion imaging, conventional imaging, clinical history, laboratory values, and outcome.
Fifteen of the 16 patients showed marked global hyperperfusion, and 1 patient showed unilateral marked hyperperfusion. Mean gray matter (GM) cerebral blood flow (CBF) in these patients was 142.6 mL/100 g of tissue per minute (ranging from 79.9 to 204.4 mL/100 g of tissue per minute). Global GM CBF was significantly higher in anoxic injury subjects, compared with age-matched control groups with and without infarction (F(2,39) = 63.11; P < .001). Three patients had global hyperperfusion sparing areas of acute infarction. Conventional imaging showed characteristic restricted diffusion in the basal ganglia (n = 10) and cortex (n = 13). Most patients examined died (n = 12), with only 4 patients surviving at the 4-month follow-up.
Pulsed ASL can dramatically demonstrate and quantify the severity of the cerebral hyperperfusion after a global anoxic injury. The global hyperperfusion probably results from loss of autoregulation of cerebral vascular resistance.
缺氧性脑损伤是长时间缺氧的灾难性后果。本研究的目的是利用动脉自旋标记（ASL）来描述脑缺氧损伤后出现的灌注模式。
对16例有缺氧或缺氧缺血性损伤病史的患者进行分析，年龄范围为1.5至78.0岁（平均50.3岁），在缺氧损伤后1.0 - 13.0天（平均4.6天）进行常规磁共振成像和脉冲ASL检查。将脉冲ASL作为标准卒中方案的一部分，对每例患者的脑灌注进行定量分析。对灌注成像、常规成像、临床病史、实验室检查值和预后进行相关性分析。
16例患者中有15例表现为明显的全脑高灌注，1例表现为单侧明显高灌注。这些患者灰质（GM）的平均脑血流量（CBF）为每分钟142.6 mL/100 g组织（范围为每分钟79.9至204.4 mL/100 g组织）。与有或无梗死的年龄匹配对照组相比，缺氧损伤患者的全脑GM CBF显著更高（F(2,39) = 63.11；P <.001）。3例患者全脑高灌注，急性梗死区域未受累。常规成像显示基底节（n = 10）和皮质（n = 13）有特征性的扩散受限。大多数接受检查的患者死亡（n = 12），在4个月的随访中只有4例患者存活。
脉冲ASL能够显著显示并量化全脑缺氧损伤后脑高灌注的严重程度。全脑高灌注可能是由于脑血管阻力自动调节功能丧失所致。
