title: Prediction of hemorrhagic transformation following acute stroke: role of diffusion- and perfusion-weighted magnetic resonance imaging.
abstract: BACKGROUND
  Acute diffusion-weighted (DWI) and perfusion-weighted (PWI) magnetic resonance imaging (MRI) findings may correlate with secondary hemorrhagic transformation (HT) risk in patients with stroke. This information could be of value, particularly in individuals being considered for thrombolytic therapy.
  
  
  OBJECTIVE
  To determine the relationship between DWI and PWI findings and the risk of secondary HT in patients with acute stroke.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  Twenty-seven patients with acute stroke capable of being evaluated with DWI/PWI 8 hours or less after symptom onset.
  
  
  METHODS
  Apparent diffusion coefficient values, perfusion delay measurements, and subsequent MRI or computed tomographic scans detected HT.
  
  
  RESULTS
  The mean +/- SD apparent diffusion coefficient of ischemic regions that experienced HT was significantly lower than the overall mean +/- SD apparent diffusion coefficient of all ischemic areas analyzed (0.510 +/- 0.140 x 10(-3) mm(2)/s vs 623 +/- 0.113 x 10(-3) mm(2)/s; P =.004). This difference remained significant when comparing the HT-destined ischemic areas with the non-HT-destined areas within the same ischemic lesion (P =.02). Patients receiving recombinant tissue-type plasminogen activator (rt-PA) experienced HT significantly earlier than patients not receiving rt-PA (P =.002). Moreover, a persistent perfusion deficit in the area of subsequent hemorrhage at 3 to 6 hours after the initial MRI scan was identified in significantly more patients who experienced HT than in those who did not (83% vs 30%; P =.03).
  
  
  CONCLUSIONS
  Both DWI and PWI scans detect abnormalities that are associated with HT. These findings support a role for MRI in identifying patients who are at increased risk for secondary HT following acute ischemic stroke.
authors: Stanford Stroke Center, Palo Alto, CA 94304, USA. dct@stanford.edu
authors: D C
authors: DC
authors: Tong
authors: A
authors: A
authors: Adami
authors: M E
authors: ME
authors: Moseley
authors: M P
authors: MP
authors: Marks
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage / Q000139:chemically induced / Q000209:etiology*; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010960:Plasminogen Activators / Q000009:adverse effects / Q000627:therapeutic use; D011379:Prognosis; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D011994:Recombinant Proteins; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator