title: Intranidal signal distribution in post-contrast time-of-flight MRA is associated with rupture risk factors in arteriovenous malformations.
abstract: OBJECTIVE
  To evaluate if arteriovenous malformations (AVMs) that are associated with a high rupture risk (HRR) are represented by different intranidal Time-of-Flight (TOF) magnetic resonance angiography intensity distributions compared to those with presumably low rupture risk (LRR).
  
  
  METHODS
  Fifty post-contrast TOF datasets of patients with an AVM were analyzed in this study. The patients were classified to the HRR group in case of a deep location, presence of exclusive deep venous drainage, previous hemorrhagic event or a combination thereof. For each TOF dataset, the AVM nidus was semi-automatically delineated and used for histogram extraction. Each histogram was analyzed by calculating the skewness, kurtosis, mean and median intensity and full-width-half-maximum. Statistical analysis was performed using parameter-wise two-sided t-tests of the parameters between the two groups.
  
  
  RESULTS
  Based on morphological analysis, 21 patients were classified to the HRR and 29 patients to the LRR group. Statistical analysis revealed that TOF intensity distributions of HRR AVMs exhibit a significant higher skewness (p=0.0005) parameter compared to LRR AVMs. Contrary to these findings, no significant differences were found for the other parameters evaluated.
  
  
  CONCLUSIONS
  Intranidal flow heterogeneity, for example, caused by turbulent flow conditions, may play an important role for risk of a hemorrhage. An analysis of post-contrast TOF intensities within the nidus of an AVM may offer simple and valuable information for clinical risk estimation of AVMs and needs to be tested prospectively.
authors.affiliation: Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. n.forkert@uke.uni-hamburg.de
authors.forename: N D
authors.initials: ND
authors.lastname: Forkert
authors.forename: J
authors.initials: J
authors.lastname: Fiehler
authors.forename: M
authors.initials: M
authors.lastname: Schönfeld
authors.forename: J
authors.initials: J
authors.lastname: Sedlacik
authors.forename: J
authors.initials: J
authors.lastname: Regelsberger
authors.forename: H
authors.initials: H
authors.lastname: Handels
authors.forename: T
authors.initials: T
authors.lastname: Illies
mesh_terms: D003287:Contrast Media; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008536:Meglumine / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012307:Risk Factors; D012422:Rupture, Spontaneous / Q000473:pathology; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine