title: Longitudinal studies of ischemic penumbra by using 18F-FDG PET and MRI techniques in permanent and transient focal cerebral ischemia in rats.
abstract: At present, the goal of stroke research is the identification of a potential recoverable tissue surrounding the ischemic core, suggested as ischemic penumbra, with the aim of applying a treatment that attenuates the growth of this area. Our purpose was to determine whether a combination of imaging techniques, including (18)F-FDG PET and MRI could identify the penumbra area. Longitudinal studies of (18)F-FDG PET and MRI were performed in rats 3 h, 24 h and 48 h after the onset of ischemia. A transient and a permanent model of focal cerebral ischemia were performed. Regions of interest were located, covering the ischemic core, the border that progresses to infarction (recruited tissue), and the border that recovers (recoverable tissue) with early reperfusion. Analyses show that permanent ischemia produces severe damage, whereas the transient ischemia model does not produce clear damage in ADC maps at the earliest time studied. The only significant differences between values for recoverable tissue, (18)F-FDG (84±2%), ADC (108±5%) and PWI (70±8%), and recruited tissue, (18)F-FDG (77±3%), ADC (109±4%) and PWI (77±4%), are shown in (18)F-FDG ratios. We also show that recoverable tissue values are different from those in non-infarcted tissue. The combination of (18)F-FDG PET, ADC and PWI MRI is useful for identification of ischemic penumbra, with (18)F-FDG PET being the most sensitive approach to its study at early times after stroke, when a clear DWI deficit is not observed.
authors.affiliation: Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Sobrado
authors.affiliation: CAI de Cartografía Cerebral Instituto Pluridisciplinar, Universidad Complutense de Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Delgado
authors.affiliation: CAI Resonancia Magnética Nuclear, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Fernández-Valle
authors.affiliation: CAI de Cartografía Cerebral Instituto Pluridisciplinar, Universidad Complutense de Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: García-García
authors.affiliation: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense de Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Torres
authors.affiliation: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense de Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Sánchez-Prieto
authors.affiliation: Unidad de Ictus, Servicio de Neurología, Hospital La Princesa, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Vivancos
authors.affiliation: Servicio de Radiodiagnóstico Sección Neurorradiología, Hospital La Princesa, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Manzanares
authors.affiliation: Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Moro
authors.affiliation: CAI de Cartografía Cerebral Instituto Pluridisciplinar, Universidad Complutense de Madrid, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Pozo
authors.affiliation: Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Spain. Electronic address: ignacio.lizasoain@med.ucm.es.
authors.forename: I
authors.initials: I
authors.lastname: Lizasoain
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives*; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D019275:Radiopharmaceuticals; C047515:2-fluoro-2-deoxyglucose-6-phosphate; D019298:Glucose-6-Phosphate