title: Optimization of single shot 3D breath-hold non-enhanced MR angiography of the renal arteries.
abstract: BACKGROUND
  Cardiac and navigator-gated, inversion-prepared non-enhanced magnetic resonance angiography techniques can accurately depict the renal arteries without the need for contrast administration. However, the scan time and effectiveness of navigator-gated techniques depend on the subject respiratory pattern, which at times results in excessively prolonged scan times or suboptimal image quality. A single-shot 3D magnetization-prepared steady-state free precession technique was implemented to allow the full extent of the renal arteries to be depicted within a single breath-hold.
  
  
  METHODS
  Technical optimization of the breath-hold technique was performed with fourteen healthy volunteers. An alternative magnetization preparation scheme was tested to maximize inflow signal. Quantitative and qualitative comparisons were made between the breath-hold technique and the clinically accepted navigator-gated technique in both volunteers and patients on a 1.5 T scanner.
  
  
  RESULTS
  The breath-hold technique provided an average of seven fold reduction in imaging time, without significant loss of image quality. Comparable single-to-noise and contrast-to-noise ratios of intra- and extra-renal arteries were found between the breath-hold and the navigator-gated techniques in volunteers. Furthermore, the breath-hold technique demonstrated good image quality for diagnostic purposes in a small number of patients in a pilot study.
  
  
  CONCLUSIONS
  The single-shot, breath-hold technique offers an alternative to navigator-gated methods for non-enhanced renal magnetic resonance angiography. The initial results suggest a potential supplementary clinical role for the breath-hold technique in the evaluation of suspected renal artery diseases.
authors.affiliation: Department of Radiology, NorthShore University HealthSystem, 2650 Ridge Avenue, Evanston, IL 60201, USA. tanhuan@gmail.com
authors.forename: Huan
authors.initials: H
authors.lastname: Tan
authors.forename: Ioannis
authors.initials: I
authors.lastname: Koktzoglou
authors.forename: Christopher
authors.initials: C
authors.lastname: Glielmi
authors.forename: Mauricio
authors.initials: M
authors.lastname: Galizia
authors.forename: Robert R
authors.initials: RR
authors.lastname: Edelman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D062485:Breath Holding; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012016:Reference Values; D012077:Renal Artery / Q000473:pathology*; D012078:Renal Artery Obstruction / Q000175:diagnosis*; D015203:Reproducibility of Results; D055815:Young Adult