title: Iron oxide particle-enhanced MRI suggests variability of brain inflammation at early stages after ischemic stroke.
abstract: OBJECTIVE
  Inflammation contributes to brain damage caused by ischemic stroke. Ultrasmall superparamagnetic iron oxide (USPIO)-enhanced MRI allows noninvasive monitoring of macrophage recruitment into ischemic brain lesions. In this study, we determined the extent of USPIO enhancement during early stages of ischemic stroke.
  
  
  METHODS
  Twelve consecutive patients with typical clinical signs of stroke underwent multimodal stroke imaging at 1.5-T within 24 hours of symptom onset. They received intravenous USPIO (ferumoxtran) infusion at 26 to 96 hours (mean, 44 hours) after stroke. A total of four follow-up MRI scans were performed 24 to 36 hours, 48 to 72 hours, 7 to 8 days, and 10 to 11 days after USPIO infusion.
  
  
  RESULTS
  Nine patients were included in the final analysis. Parenchymal USPIO enhancement occurred in 3 of 9 analyzed patients and was mainly evident on T1-weighted spin-echo images. USPIO-dependent signal changes were spatially heterogeneous, reflecting the distinct patterns of hematogenous macrophage infiltration in different lesion types.
  
  
  CONCLUSIONS
  Our findings suggest a variable extent and distribution of macrophage infiltration into early ischemic stroke lesions. USPIO-enhanced MRI may help to more specifically target antiinflammatory therapy in patients with stroke.
authors: Institute of Diagnostic Radiology, Heinrich-Heine-University, Moorenstr. 5, D-40225 Düsseldorf, Germany.
authors: Andreas
authors: A
authors: Saleh
authors: Michael
authors: M
authors: Schroeter
authors: Adrian
authors: A
authors: Ringelstein
authors: Hans-Peter
authors: HP
authors: Hartung
authors: Mario
authors: M
authors: Siebler
authors: Ulrich
authors: U
authors: Mödder
authors: Sebastian
authors: S
authors: Jander
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000276:immunology / Q000473:pathology*; D003287:Contrast Media; D003911:Dextrans; D042241:Early Diagnosis; D004660:Encephalitis / Q000276:immunology / Q000473:pathology*; D005260:Female; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron; D008264:Macrophages / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D010087:Oxides; D020521:Stroke / Q000276:immunology / Q000473:pathology*
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide