title: 3D whole-heart coronary MR angiography at 1.5T in healthy volunteers: comparison between unenhanced SSFP and Gd-enhanced FLASH sequences.
abstract: OBJECTIVE
  To validate the optimal cardiac phase and appropriate acquisition window for three-dimensional (3D) whole-heart coronary magnetic resonance angiography (MRA) with a steady-state free precession (SSFP) sequence, and to compare image quality between SSFP and Gd-enhanced fast low-angle shot (FLASH) MR techniques at 1.5 Tesla (T).
  
  
  METHODS
  Thirty healthy volunteers (M:F = 25:5; mean age, 35 years; range, 24-54 years) underwent a coronary MRA at 1.5T. 3D whole-heart coronary MRA with an SSFP was performed at three different times: 1) at end-systole with a narrow (120-msec) acquisition window (ESN), 2) mid-diastole with narrow acquisition (MDN); and 3) mid-diastole with wide (170-msec) acquisition (MDW). All volunteers underwent a contrast enhanced coronary MRA after undergoing an unenhanced 3D true fast imaging with steady-state precession (FISP) MRA three times. A contrast enhanced coronary MRA with FLASH was performed during MDN. Visibility of the coronary artery and image quality were evaluated for 11 segments, as suggested by the American Heart Association. Image quality was scored by a five-point scale (1 = not visible to 5 = excellent). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated at the proximal coronary arteries.
  
  
  RESULTS
  The SSFP sequence rendered higher visibility coronary segments, higher image quality, as well as higher SNR and CNR than the Gd-enhanced FLASH technique at 1.5T (p < 0.05). The visibility of coronary segments, image quality, SNR and CNR in the ESN, MDN and MDW with SSFP sequence did not differ significantly.
  
  
  CONCLUSIONS
  An SSFP sequence provides an excellent method for the 3D whole-heart coronary MRA at 1.5T. Contrast enhanced coronary MRA using the FLASH sequence does not help improve the visibility of coronary segments, image quality, SNR or CNR on the 3D whole-heart coronary MRA.
authors: Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul 135-720, Korea.
authors: Hye Mi
authors: HM
authors: Gweon
authors: Sang Jin
authors: SJ
authors: Kim
authors: Sang Min
authors: SM
authors: Lee
authors: Yoo Jin
authors: YJ
authors: Hong
authors: Tae Hoon
authors: TH
authors: Kim
mesh_terms: D000328:Adult; D003287:Contrast Media; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D005682:Gadolinium; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D012016:Reference Values; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D005682:Gadolinium