title: Collateral flow in coarctation of the aorta with magnetic resonance velocity mapping: correlation to morphological imaging of collateral vessels.
abstract: OBJECTIVE
  To correlate quantification of collateral flow in aortic coarctation with the morphological visualization of the collateral vessels and to compare different approaches to measurement of collateral flow.
  
  
  METHODS
  Thirteen children with coarctation were examined with T1-weighted spin-echo (T1-W SE) imaging and 3D contrast-enhanced magnetic resonance angiography (MRA). MR velocity mapping was performed at four levels in the descending aorta.
  
  
  RESULTS
  The flow immediately above and below the coarctation did not differ significantly. Measuring within the coarctation resulted in flow overestimation. The increase of flow from proximal to distal aorta was 12 +/- 21% in patients with no or uncertain collaterals and 69 +/- 55% in patients with pronounced collaterals. Spin-echo images and MRA were comparable in visualizing collateral vessels. The visual estimation of collaterals correlated reasonably well with flow quantification MR velocity mapping.
  
  
  CONCLUSIONS
  Collateral flow assessment with MR velocity mapping is an accurate technique for evaluating the hemodynamic importance of a coarctation and is recommended if abundant collaterals are not visualized with spin echo or MRA.
authors.affiliation: Diagnostic Center of Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden. catarina.holmqvist@drad.lu.se
authors.forename: Catarina
authors.initials: C
authors.lastname: Holmqvist
authors.forename: Freddy
authors.initials: F
authors.lastname: Ståhlberg
authors.forename: Katarina
authors.initials: K
authors.lastname: Hanséus
authors.forename: Peter
authors.initials: P
authors.lastname: Hochbergs
authors.forename: Staffan
authors.initials: S
authors.lastname: Sandström
authors.forename: Elna-Marie
authors.initials: EM
authors.lastname: Larsson
authors.forename: Sven
authors.initials: S
authors.lastname: Laurin
mesh_terms: D001017:Aortic Coarctation / Q000503:physiopathology*; D001783:Blood Flow Velocity; D002648:Child; D002675:Child, Preschool; D003097:Collateral Circulation / Q000502:physiology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007223:Infant; D007231:Infant, Newborn; D016014:Linear Models; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media