title: High-resolution magnetic resonance angiography of the renal arteries using parallel imaging acquisition techniques at 3.0 T: initial experience.
abstract: OBJECTIVE
  The purpose of this prospective study was to investigate the feasibility of high-resolution magnetic resonance angiography (MRA) of the kidneys at 3.0 T using parallel data acquisition.
  
  
  METHODS
  Contrast-enhanced MRA of the renal arteries (RA) was performed in 12 volunteers and 12 consecutive patients (mean age 47.1 +/- 16.3 years) on a 3.0 T MR scanner. For CEMRA, a high-resolution 3-dimensional GRE FLASH sequence was implemented. Images were assessed subjectively on a 0 to 5 scoring scale by 2 reviewers. Quantitative evaluation was done by measuring the contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR).
  
  
  RESULTS
  Diagnostic image quality was acquired in all individuals. In total, 62 RA were found, consisting of 48 main and 14 accessory RA. Overall visibility score for main RA was 4.82 +/- 0.38. RA were identified up to the third-order branches in 88%. In 3 of 12 patients, a hemodynamic relevant stenosis was found and proven by conventional angiogram.
  
  
  CONCLUSIONS
  CEMRA at 3.0 T is advantageous in terms of better SNR and T1 weighting; therefore, measurement time can be reduced and spatial resolution can be increased without corruption of signal yield. Consequently, high-field MRA may be preferred for the evaluation of renal vascular anatomy in potential kidney donors or for the detection of renal artery stenosis.
authors.affiliation: Department of Cardiovascular MR Research, University of Los Angeles, Los Angeles, California, USA. ulrich.kramer@med.uni-tuebingen.de
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kramer
authors.forename: Kambiz
authors.initials: K
authors.lastname: Nael
authors.forename: Gerhard
authors.initials: G
authors.lastname: Laub
authors.forename: Glen K
authors.initials: GK
authors.lastname: Nyborg
authors.forename: Michael
authors.initials: M
authors.lastname: Fenchel
authors.forename: Stephan
authors.initials: S
authors.lastname: Miller
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: J Paul
authors.initials: JP
authors.lastname: Finn
mesh_terms: D000328:Adult; D000368:Aged; D001012:Aorta, Abdominal / Q000473:pathology; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D005682:Gadolinium; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012077:Renal Artery / Q000473:pathology*; D012078:Renal Artery Obstruction / Q000175:diagnosis*
chemical_list: D003287:Contrast Media; D005682:Gadolinium