title: Time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla for evaluation of hemodynamic characteristics of vascular malformations: description of distinct subgroups.
abstract: OBJECTIVE
  Quantitative evaluation of hemodynamic characteristics of arteriovenous and venous malformations using time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla.
  
  
  METHODS
  Time-resolved MRA with interleaved stochastic trajectories (TWIST) at 3.0 Tesla was studied in 83 consecutive patients with venous malformations (VM) and arteriovenous malformations (AVM). Enhancement characteristics were calculated as percentage increase of signal intensity above baseline over time. Maximum percentage signal intensity increase (signalmax), time intervals between onset of arterial enhancement and lesion enhancement (tonset), and time intervals between beginning of lesion enhancement and maximum percentage of lesion enhancement (tmax) were analyzed.
  
  
  RESULTS
  All AVMs showed a high-flow hemodynamic pattern. Two significantly different (p < 0.001) types of venous malformations emerged: VMs with arteriovenous fistulas (AVF) (median signalmax737 %, IQR [interquartile range] = 511 - 1182 %; median tonset5 s, IQR = 5 - 10 s; median tmax35 s, IQR = 26 - 40 s) and without AVFs (median signalmax284 %, IQR = 177-432 %; median tonset23 s, IQR = 15 - 30 s; median tmax60 s, IQR = 55 - 75 s).
  
  
  CONCLUSIONS
  Quantitative evaluation of time-resolved MRA at 3.0 Tesla provides hemodynamic characterization of vascular malformations. VMs can be subclassified into two hemodynamic subgroups due to presence or absence of AVFs.
  
  
  CONCLUSIONS
  • Time-resolved MRA at 3.0 Tesla provides quantitative hemodynamic characterization of vascular malformations. • Malformations significantly differ in time courses of enhancement and signal intensity increase. • AVMs show a distinctive high-flow hemodynamic pattern. • Two significantly different types of VMs emerged: VMs with and without AVFs.
authors.affiliation: Department of Radiology, University Hospital Regensburg, 93042, Regensburg, Germany. simone.hammer@ukr.de.
authors.forename: Simone
authors.identifier: http://orcid.org/0000-0003-2326-9734
authors.initials: S
authors.lastname: Hammer
authors.affiliation: Department of Radiology, University Hospital Regensburg, 93042, Regensburg, Germany.|Division of Vascular and Interventional Radiology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA.
authors.forename: Wibke
authors.initials: W
authors.lastname: Uller
authors.affiliation: Department of Nuclear Medicine, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080, Würzburg, Germany.
authors.forename: Florentine
authors.initials: F
authors.lastname: Manger
authors.affiliation: Department of Radiology, University Hospital Regensburg, 93042, Regensburg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fellner
authors.affiliation: Center for Clinical Trials, University Hospital Regensburg, 93042, Regensburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Zeman
authors.affiliation: Department of Radiology, University Hospital Regensburg, 93042, Regensburg, Germany.
authors.forename: Walter A
authors.initials: WA
authors.lastname: Wohlgemuth
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007223:Infant; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D054079:Vascular Malformations / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055815:Young Adult
keywords: Arteriovenous fistula; Arteriovenous malformation; Magnetic resonance angiography; Magnetic resonance imaging; Vascular malformation