title: Changes in AVM angio-architecture and hemodynamics after stereotactic radiosurgery assessed by dynamic MRA and phase contrast flow assessments: a prospective follow-up study.
abstract: OBJECTIVE
  Assessment of changes in the hemodynamics of Arteriovenous malformations (AVM) induced by radiosurgery by MR Phase contrast (PC) measurements of the internal carotid arteries (ICA).
  
  
  METHODS
  65 patients shortly after or before stereotactic radiosurgery underwent MRI including morphological series, MR-Angiography (Time-of-flight, dynamic MRA) and bilateral ECG triggered MR phase contrast (PC) measurements of the ICA. Follow-up was performed in 34 patients. The observation period was up to 4 years.
  
  
  RESULTS
  Over all subjects, a significant relationship between mean arterial blood flow in the ICA on the side of the lesion and AVM volume was revealed (p = 0,0002). In large (>10 ccm) and medium-sized AVMs, (>3, 5 ≤ 10 ccm) the blood flow was significantly increased on the side of the AVM (p = 0,0004; p = 0,047), whereas in lesions <3, 5 ccm, no significant rise of the mean blood flow was detectable. At follow-up, the mean blood flow in the ipsilateral artery was not increased anymore compared to the contralateral ICA (p = 0,11). These changes correlated with a significant reduction of the average AVM volume (p = 0, 0026).
  
  
  CONCLUSIONS
  The AVM angioarchitecture has significant impact on the blood flow in feeding arteries. A significant reduction of the shunt volume by successful radiotherapy leads to normalization of the hemodynamics.
authors.affiliation: Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. l.schuster@dkfz-heidelberg.de
authors.forename: Lydia
authors.initials: L
authors.lastname: Schuster
authors.forename: E
authors.initials: E
authors.lastname: Schenk
authors.forename: F
authors.initials: F
authors.lastname: Giesel
authors.forename: T
authors.initials: T
authors.lastname: Hauser
authors.forename: L
authors.initials: L
authors.lastname: Gerigk
authors.forename: A
authors.initials: A
authors.lastname: Zabel-Du-Bois
authors.forename: Marco
authors.initials: M
authors.lastname: Essig
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D002648:Child; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery; D016896:Treatment Outcome; D055815:Young Adult