Anoxic Injury-Associated Cerebral Hyperperfusion Identified with Arterial Spin-Labeled MR Imaging

• Published in: American journal of neuroradiology : AJNR Vol. 29; no. 7; pp. 1302 - 1307
• Main Authors: Pollock, J.M, Whitlow, C.T, Deibler, A.R, Tan, H, Burdette, J.H, Kraft, R.A, Maldjian, J.A
• Format: Journal Article
• Language: English
• Published: Oak Brook, IL Am Soc Neuroradiology 01.08.2008; American Society of Neuroradiology
• Subjects: Adolescent; Adult; Aged; Biological and medical sciences; Blood Flow Velocity - physiology; Brain; Brain - blood supply; Cerebrospinal fluid. Spinal cord. Spinal roots. Spinal nerves; Child; Child, Preschool; Dominance, Cerebral - physiology; Female; Heart Arrest - complications; Heart Arrest - physiopathology; Homeostasis - physiology; Humans; Hyperemia - diagnosis; Hyperemia - physiopathology; Hypoxia, Brain - diagnosis; Hypoxia, Brain - etiology; Hypoxia, Brain - physiopathology; Image Enhancement - methods; Image Processing, Computer-Assisted - methods; Infant; Infarction, Middle Cerebral Artery - diagnosis; Infarction, Middle Cerebral Artery - physiopathology; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Angiography - methods; Male; Medical sciences; Middle Aged; Nervous system; Neurosurgery; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Regional Blood Flow - physiology; Retrospective Studies; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Vascular Resistance - physiology; Oxygen; Nervous system diseases; Anoxia; Radiodiagnosis; Central nervous system; Nuclear magnetic resonance imaging; Encephalon
• ISSN: 0195-6108; 1936-959X; 1936-959X
• DOI: 10.3174/ajnr.A1095

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.