title: Prospective Study of Early MRI Appearances following Flow-Diverting Stent Placement for Intracranial Aneurysms.
abstract: OBJECTIVE
  MR imaging findings of aneurysm enlargement, aneurysm wall enhancement, perianeurysmal edema, and embolic phenomena following deployment of flow-diverting stents may be relevant to those patients who subsequently experience procedure-related intracranial hemorrhage. We sought to document the routine early postoperative MR imaging findings following flow-diverting stent insertion.
  
  
  METHODS
  Patients requiring flow-diverting stent placement for treatment or retreatment of cerebral aneurysms were prospectively included in the study during a 26-month period. Early postprocedural MR imaging studies were obtained and compared with preoperative imaging. Patient clinical outcome data were also collected.
  
  
  RESULTS
  There were 34 stent-placement procedures during the study period. Aneurysm mural enhancement and mild new perianeurysmal edema were present in 50% and 14%, respectively. Any DWI lesion was present in 57% of cases. New or possibly new foci of susceptibility effect were found ipsilateral to the stent and not associated with diffusion restriction in 66% of cases. There were 2 cases (6%) of parenchymal hemorrhage and 2 major clinical complications (6%) causing permanent morbidity.
  
  
  CONCLUSIONS
  Asymptomatic aneurysm mural enhancement is frequently seen following flow-diverting stent placement and should not necessarily be interpreted as a sign of impending aneurysm rupture. This finding often persists despite complete aneurysm occlusion. New small brain parenchymal susceptibility foci following stent placement have not previously been reported, to our knowledge, but were common in our series.
authors.affiliation: From the Department of Radiology (B.J.M., J.K.H.), Auckland City Hospital, Auckland, New Zealand benmcg@gmail.com.
authors.forename: B J
authors.initials: BJ
authors.lastname: McGuinness
authors.affiliation: Department of Radiology (S.M.), Vancouver General Hospital, Vancouver, British Columbia, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Memon
authors.affiliation: From the Department of Radiology (B.J.M., J.K.H.), Auckland City Hospital, Auckland, New Zealand.
authors.forename: J K
authors.initials: JK
authors.lastname: Hope
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D019233:Retreatment; D015607:Stents; D016896:Treatment Outcome