title: Dynamic perfusion and diffusion MRI of cortical spreading depolarization in photothrombotic ischemia.
abstract: Cortical spreading depolarization (CSD) is known to exacerbate ischemic damage, as the number of CSDs correlates with the final infarct volumes and suppressing CSDs improves functional outcomes. To investigate the role of CSD in ischemic damage, we developed a novel rat model of photothrombotic ischemia using a miniature implantable optic fiber that allows lesion induction inside the magnetic resonance imaging (MRI) scanner. We were able to precisely control the location and the size of the ischemic lesion, and continuously monitor dynamic perfusion and diffusion MRI signal changes at high temporal resolution before, during and after the onset of focal ischemia. Our model showed that apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) in the ischemic core dropped immediately after lesion onset by 20±6 and 41±23%, respectively, and continually declined over the next 5h. Meanwhile, CSDs were observed in all animals (n=36) and displayed either a transient decrease of ADC by 17±3% or an increase of CBF by 104±15%. All CSDs were initiated from the rim of the ischemic core, propagated outward, and confined to the ipsilesional cortex. Additionally, we demonstrated that by controlling the size of perfusion-diffusion mismatch (which approximates the penumbra) in our model, the number of CSDs correlated with the mismatch area rather than the final infarct volume. This study introduces a novel platform to study CSDs in real-time with high reproducibility using MRI.
authors: Department of Neurology, University of North Carolina, Chapel Hill, NC, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA.
authors: Yu-Chieh Jill
authors: YC
authors: Kao
authors: Department of Neurology, University of North Carolina, Chapel Hill, NC, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA; Department of Geriatrics, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
authors: Wenjing
authors: W
authors: Li
authors: Department of Neurology, University of North Carolina, Chapel Hill, NC, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA.
authors: Hsin-Yi
authors: HY
authors: Lai
authors: Department of Neurology, University of North Carolina, Chapel Hill, NC, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA; Neurobiology Curriculum, University of North Carolina, Chapel Hill, NC, USA.
authors: Esteban A
authors: EA
authors: Oyarzabal
authors: Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA; Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA; Department of Radiology, University of North Carolina, Chapel Hill, NC, USA.
authors: Weili
authors: W
authors: Lin
authors: Department of Neurology, University of North Carolina, Chapel Hill, NC, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA; Neurobiology Curriculum, University of North Carolina, Chapel Hill, NC, USA; Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA; McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA. Electronic address: shihy@unc.edu.
authors: Yen-Yu Ian
authors: YY
authors: Shih
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002545:Brain Ischemia / Q000175:diagnosis* / Q000209:etiology; D002540:Cerebral Cortex / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D013181:Cortical Spreading Depression / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging; D004195:Disease Models, Animal; D020244:Infarction, Middle Cerebral Artery / Q000150:complications; D007834:Lasers / Q000009:adverse effects; D018810:Magnetic Resonance Angiography; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012395:Rose Bengal; D013997:Time Factors
chemical_list: D012395:Rose Bengal
keywords: Cortical spreading depolarization; Diffusion MRI; Ischemia; Perfusion MRI; Rat