title: Various patterns of perfusion-weighted MR imaging and MR angiographic findings in hyperacute ischemic stroke.
abstract: OBJECTIVE
  Various clinical subtypes of patients presenting with sudden-onset ischemic stroke have been recognized, but classification of those types is not simple. We identified various patterns of perfusion-weighted MR imaging and MR angiographic findings in hyperacute ischemic stroke with relation to clinical outcomes.
  
  
  METHODS
  Twelve patients with symptoms of acute ischemic stroke due to middle cerebral artery occlusion underwent perfusion-weighted MR imaging and MR angiography within 6 hours after the onset of symptoms. Perfusion-weighted imaging was performed with a conventional dynamic contrast-enhanced T2*-weighted sequence, and cerebral blood volume (CBV) maps were then created. CBV maps and MR angiographic findings were compared with 99mTc-HMPAO brain SPECT scans, short-term outcomes, and follow-up imaging findings.
  
  
  RESULTS
  The combined CBV and MR angiographic findings were classified into three patterns: arterial occlusion and decreased CBV (n = 8), arterial occlusion and increased CBV (n = 2), and no arterial occlusion and normal CBV (n = 2). These three patterns were strongly related to SPECT findings, short-term outcomes, and follow-up imaging findings. Perfusion on SPECT decreased markedly in the affected regions in all patients with the first pattern, decreased slightly in the second pattern, and was normal in the third pattern. Symptoms were not significantly changed at 24 hours after onset in any of the patients with the first pattern, but resolved completely in all patients with the latter two patterns. Follow-up imaging showed large infarctions in all patients with the first pattern. Initially, no infarction was seen in the second pattern, but watershed infarction developed later in one of these patients.
  
  
  CONCLUSIONS
  Hyperacute ischemic stroke may be differentiated into three imaging patterns with different clinical outcomes. The combined use of perfusion-weighted MR imaging and MR angiography may play a substantial role in guiding the choice of treatment of this disease.
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000150:complications; D001810:Blood Volume / Q000502:physiology; D002545:Brain Ischemia / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D002539:Cerebral Arterial Diseases / Q000150:complications; D002544:Cerebral Infarction / Q000175:diagnosis / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology; D002561:Cerebrovascular Disorders / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010347:Patient Care Planning; D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome