title: Temporal and anatomical variations of brain water apparent diffusion coefficient in perinatal cerebral hypoxic-ischemic injury: relationships to cerebral energy metabolism.
abstract: Cerebral apparent diffusion coefficients (ADCs) were determined in nine newborn piglets before and for 48 h after transient hypoxia-ischemia. Phosphorus MRS revealed severely reduced cerebral energy metabolism during the insult and an apparently complete recovery 2 h after resuscitation commenced. At this time, mean ADC over the imaging slice (ADCglobal) was 0.88 (0.04) x 10(-9) m2 x s(-1) (mean (SD)), which was close to the baseline value of 0.92 (0.4) x 10(-9) m2 x s(-1). In seven of the animals, a "secondary" failure of energy metabolism then evolved, accompanied by a decline in ADCglobal to 0.64 (0.17) x 10(-9) m2 x s(-1) at 46 h postresuscitation (P < 0.001 versus baseline). For these seven animals, ADCglobal correlated linearly with the concentration ratio [phosphocreatine (PCr)]/[inorganic phosphate (Pi)] (0.94 < r < 0.99; P < 0.001). A nonlinear relationship was demonstrated between ADCglobal and the concentration ratio [nucleotide triphosphate (NTP)]/[Pi + PCr + 3 NTP]. The ADC reduction commenced in the parasagittal cortex before spreading in a characteristic pattern throughout the brain. ADC seems to be closely related to cerebral energy status and shows considerable potential for the assessment of hypoxic-ischemic injury in the newborn brain.
authors.affiliation: Department of Medical Physics, University College London, United Kingdom.
authors.forename: J S
authors.initials: JS
authors.lastname: Thornton
authors.forename: R J
authors.initials: RJ
authors.lastname: Ordidge
authors.forename: J
authors.initials: J
authors.lastname: Penrice
authors.forename: E B
authors.initials: EB
authors.lastname: Cady
authors.forename: P N
authors.initials: PN
authors.lastname: Amess
authors.forename: S
authors.initials: S
authors.lastname: Punwani
authors.forename: M
authors.initials: M
authors.lastname: Clemence
authors.forename: J S
authors.initials: JS
authors.lastname: Wyatt
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001238:Asphyxia Neonatorum / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D001812:Blood-Brain Barrier / Q000502:physiology*; D001834:Body Water / Q000378:metabolism*; D001921:Brain / Q000098:blood supply / Q000473:pathology; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D001929:Brain Edema / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D004058:Diffusion; D006801:Humans; D002534:Hypoxia, Brain / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D007231:Infant, Newborn; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D019047:Phantoms, Imaging; D010710:Phosphates / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D013552:Swine
chemical_list: D010710:Phosphates; D010725:Phosphocreatine