Cerebral blood oxygenation in rat brain during hypoxic hypoxia. Quantitative MRI of effective transverse relaxation rates.
Oxygenation-sensitive MRI of respiratory challenges in the brain of experimental animals will considerably benefit from a quantitative relationship between cerebral blood oxygenation and MRI parameters. Here, a multi-echo gradient-echo MRI technique was used to determine effective transverse relaxation rates R2* = 1/T2* of rat brain in vivo during short periods of hypoxia and interleaved normoxic phases. The differential contribution delta R2* observed during hypoxia was found to increase linearly with arterial blood deoxygenation for mild to moderate conditions. Severe deoxygenation resulted in a plateau most likely due to enhanced cerebral blood flow.
Prielmeier
F
F
Biomedizinische NMR Forschungs GmbH, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
Nagatomo
Y
Y
Frahm
J
J
D000818:Animals; D001160:Arterioles / Q000503:physiopathology; D001479:Basal Ganglia / Q000098:blood supply / Q000378:metabolism; D001921:Brain / Q000098:blood supply* / Q000378:metabolism; D002540:Cerebral Cortex / Q000098:blood supply / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology*; D000860:Hypoxia / Q000097:blood* / Q000503:physiopathology*; D002534:Hypoxia, Brain / Q000097:blood / Q000503:physiopathology; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008833:Microcirculation / Q000502:physiology; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D014699:Venules / Q000503:physiopathology
D010100:Oxygen