title: Imaging of arteriovenous malformation following stereotactic radiosurgery.
abstract: BACKGROUND
  Stereotactic radiosurgery allows for a high dose of focused radiation to be delivered to a small lesion such as an arteriovenous malformation (AVM). The clinical change and brain response over time to this localized high-dose radiation can be quite striking.
  
  
  OBJECTIVE
  The objective of this study to describe and analyse the imaging changes following radiotherapy for AVMs.
  
  
  METHODS
  The clinical presentation and the imaging changes following radiotherapy in two patients were studied over the course of 1-2 years.
  
  
  RESULTS
  The imaging findings include diffuse low attenuation and contrast enhancement on CT. High-signal lesions were apparent on T2-weighted MR images with prominent contrast enhancement on T1-weighted images. Ring enhancement occurred over time. While new changes appeared over 12 months, these changes diminished during the second year.
  
  
  CONCLUSIONS
  Radiotherapy induces inflammatory changes that are generally reversible but can lead to parenchymal destruction. These imaging changes are often nonspecific and therefore must be interpreted in light of clinical symptomatology and the time course since treatment. These patients should receive routine MR imaging within 3 months after radiosurgery with follow-up imaging at 6, 12, and 18 months.
authors.affiliation: Department of Pediatric Imaging, Children's Hospital of Michigan, Detroit, MI 48201-2196, USA.
authors.forename: J V
authors.initials: JV
authors.lastname: Tranchida
authors.forename: C J
authors.initials: CJ
authors.lastname: Mehall
authors.forename: T L
authors.initials: TL
authors.lastname: Slovis
authors.forename: M
authors.initials: M
authors.lastname: Lis-Planells
mesh_terms: D001921:Brain / Q000473:pathology; D002533:Cerebral Angiography; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D016634:Radiosurgery; D013997:Time Factors; D014057:Tomography, X-Ray Computed