title: Comparison of 1.5 and 3.0 T for contrast-enhanced pulmonary magnetic resonance angiography.
abstract: OBJECTIVE
  In a recent multi-center trial of gadolinium contrast-enhanced magnetic resonance angiography (Gd-MRA) for diagnosis of acute pulmonary embolism (PE), two centers utilized a common MRI platform though at different field strengths (1.5T and 3T) and realized a signal-to-noise gain with the 3T platform. This retrospective analysis investigates this gain in signal-to-noise of pulmonary vascular targets.
  
  
  METHODS
  Thirty consecutive pulmonary MRA examinations acquired on a 1.5T system at one institution were compared to 30 consecutive pulmonary MRA examinations acquired on a 3T system at a different institution. Both systems were from the same MRI manufacturer and both used the same Gd-MRA pulse sequence, although there were some protocol adjustments made due to field strength differences. Region-of-interests were manually defined on the main pulmonary artery, 4 pulmonary veins, thoracic aorta, and background lung for objective measurement of signal-to-noise, contrast-to-noise, and bolus timing bias between centers.
  
  
  RESULTS
  The 3T pulmonary MRA protocol achieved higher spatial resolution yet maintained significantly higher signal-to-noise ratio (≥13%, p = 0.03) in the main pulmonary vessels relative to 1.5T. There was no evidence of operator bias in bolus timing or patient hemodynamic differences between groups.
  
  
  CONCLUSIONS
  Relative to 1.5T, higher spatial resolution Gd-MRA can be achieved at 3T with a sustained or greater signal-to-noise ratio of enhanced vasculature.
authors: Department of Radiology, University of Michigan, Ann Arbor, 48109, USA. flondy@umich.edu
authors: Frank Joseph
authors: FJ
authors: Londy
authors: Suzan
authors: S
authors: Lowe
authors: Paul D
authors: PD
authors: Stein
authors: John G
authors: JG
authors: Weg
authors: Robert L
authors: RL
authors: Eisner
authors: Kenneth V
authors: KV
authors: Leeper
authors: Pamela K
authors: PK
authors: Woodard
authors: H Dirk
authors: HD
authors: Sostman
authors: Kathleen A
authors: KA
authors: Jablonski
authors: Sarah E
authors: SE
authors: Fowler
authors: Charles A
authors: CA
authors: Hales
authors: Russell D
authors: RD
authors: Hull
authors: Alexander
authors: A
authors: Gottschalk
authors: David P
authors: DP
authors: Naidich
authors: Thomas L
authors: TL
authors: Chenevert
mesh_terms: D001013:Aorta, Thoracic / Q000473:pathology; D017326:Clinical Trials, Phase III as Topic / Q000706:statistics & numerical data; D003287:Contrast Media; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement; D008168:Lung / Q000098:blood supply*; D060526:Magnetic Fields; D018810:Magnetic Resonance Angiography / Q000295:instrumentation* / Q000379:methods; D015337:Multicenter Studies as Topic / Q000706:statistics & numerical data; D011651:Pulmonary Artery / Q000473:pathology; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000473:pathology; D011667:Pulmonary Veins / Q000473:pathology; D012189:Retrospective Studies; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media; D005682:Gadolinium