title: Steady-state free precession MRA of the renal arteries: breath-hold and navigator-gated techniques vs. CE-MRA.
abstract: OBJECTIVE
  To explore the use of breath-hold and navigator-gated noncontrast Steady State Free Precession (SSFP) MR angiography (MRA) protocols for the evaluation of renal artery stenosis (RAS).
  
  
  METHODS
  Twenty patients referred to rule out RAS were imaged using two breath-hold and one navigator-gated SSFP MRA sequences. All patients underwent contrast-enhanced MRA (CE-MRA). Two radiologists evaluated all sequences both qualitatively (blur, artifacts, reader confidence) and quantitatively (maximum stenosis). Using CE-MRA as truth, a receiver operating characteristics (ROC) curve was generated and a statistical analysis of navigator-gated SSFP (Nav SSFP) was performed.
  
  
  RESULTS
  Seven patients had >50% renal artery stenosis by CE-MRA. Nav SSFP performed significantly better than either breath-hold SSFP technique in terms of blur, artifacts, and reader confidence. Using a 50% threshold for stenosis, sensitivity for detecting RAS was 100%, with a specificity of 85% and a negative predictive value of 100%. The average mean stenosis difference between Nav SSFP and CE-MRA was 9 +/- 9%.
  
  
  CONCLUSIONS
  Nav SSFP outperformed breath-hold SSFP in measures of image quality and reader confidence. Sensitivity and negative predictive value for detecting RAS with Nav SSFP was perfect, with an acceptable specificity of 85%. This suggests further study is warranted to evaluate Nav SSFP as a noncontrast screening technique for renal artery stenosis.
authors: Puget Sound VA Health Care System, Department of Radiology, Seattle, Washington, USA. jmaki@u.washington.edu
authors: Jeffrey H
authors: JH
authors: Maki
authors: Gregory J
authors: GJ
authors: Wilson
authors: William B
authors: WB
authors: Eubank
authors: David J
authors: DJ
authors: Glickerman
authors: Sudhakar
authors: S
authors: Pipavath
authors: Romhild M
authors: RM
authors: Hoogeveen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000494:pharmacology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D011871:Radiology / Q000379:methods*; D012077:Renal Artery / Q000473:pathology; D012078:Renal Artery Obstruction / Q000175:diagnosis* / Q000473:pathology*; D015203:Reproducibility of Results; D012119:Respiration
chemical_list: D003287:Contrast Media