title: Diagnostic value of the flow profile in the distal descending aorta by phase-contrast magnetic resonance for predicting severe coarctation of the aorta.
abstract: OBJECTIVE
  To compare aortic flow profiles at the level of the proximal descending (PDAo) and distal descending aorta (DDAo) in patients investigated for coarctation of the aorta (CoA), and compare their respective diagnostic value for predicting severe CoA. Diastolic flow decay in the PDAo predicts severe CoA, but flow measurements at this level are limited by flow turbulence, aliasing, and stent-related artifacts.
  
  
  METHODS
  We studied 49 patients evaluated for CoA with phase contrast magnetic resonance imaging (PC-MRI). Parameters of diastolic flow decay in the PDAo and DDAo were compared. Their respective diagnostic value was compared with the standard reference of transcatheter peak gradient ≥20 mmHg.
  
  
  RESULTS
  Flow measurement in the PDAo required repeated acquisition with adjustment of encoding velocity or location of the imaging plane in 69% of patients; measurement in the DDAo was achieved in single acquisition in all cases. Parameters of diastolic flow decay in the PDAo and DDAo, including rate-corrected (RC) deceleration time and RC flow deceleration yielded a good correlation (r = 0.78; P < 0.01, and r = 0.92; P < 0.01), and a similar diagnostic value for predicting severe CoA. The highest diagnostic accuracy was achieved by RC deceleration time at DDAo (sensitivity 85%, specificity 85%).
  
  
  CONCLUSIONS
  Characterization of aortic flow profiles at the DDAo offers a quick and reliable noninvasive means of assessing hemodynamically significant CoA.
authors: Department of Radiology, University Hospital of California, San Francisco, California 94143-0628, USA. muzzarellis@uhbs.ch
authors: Stefano
authors: S
authors: Muzzarelli
authors: Karen Gomes
authors: KG
authors: Ordovas
authors: Michael D
authors: MD
authors: Hope
authors: Jeffery J
authors: JJ
authors: Meadows
authors: Charles B
authors: CB
authors: Higgins
authors: Alison Knauth
authors: AK
authors: Meadows