title: Fat signal suppression for coronary MRA at 3T using a water-selective adiabatic T2 -preparation technique.
abstract: OBJECTIVE
  To improve fat saturation in coronary MRA at 3T by using a spectrally selective adiabatic T2 -Prep (WSA-T2 -Prep).
  
  
  METHODS
  A conventional adiabatic T2 -Prep (CA-T2 -Prep) was modified, such that the excitation and restoration pulses were of differing bandwidths. On-resonance spins are T2 -Prepared, whereas off-resonance spins, such as fat, are spoiled. This approach was combined with a CHEmically Selective Saturation (CHESS) pulse to achieve even greater fat suppression. Numerical simulations were followed by phantom validation and in vivo coronary MRA.
  
  
  RESULTS
  Numerical simulations demonstrated that augmenting a CHESS pulse with a WSA-T2 -Prep improved robustness to B1 inhomogeneities and that this combined fat suppression was effective over a broader spectral range than that of a CHESS pulse in a conventional T2 -Prepared sequence. Phantom studies also demonstrated that the WSA-T2 -Prep+CHESS combination produced greater fat suppression across a range of B1 values than did a CA-T2 -Prep+CHESS combination. Lastly, in vivo measurements demonstrated that the contrast-to-noise ratio between blood and myocardium was not adversely affected by using a WSA-T2 -Prep, despite the improved abdominal and epicardial fat suppression. Additionally, vessel sharpness improved.
  
  
  CONCLUSIONS
  The proposed WSA-T2 -Prep method was shown to improve fat suppression and vessel sharpness as compared to a CA-T2 -Prep technique, and to also increase fat suppression when combined with a CHESS pulse.
authors.affiliation: Department of Radiology, University Hospital (CHUV) / University of Lausanne (UNIL), Lausanne, VD, Switzerland; CardioVascular Magnetic Resonance (CVMR), Research Centre, Centre for BioMedical Imaging (CIBM), Lausanne, VD, Switzerland.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Coristine
authors.forename: Ruud B
authors.initials: RB
authors.lastname: van Heeswijk
authors.forename: Matthias
authors.initials: M
authors.lastname: Stuber
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology; D000328:Adult; D055424:Cardiac-Gated Imaging Techniques; D003198:Computer Simulation; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D064368:Healthy Volunteers; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging
keywords: T2-Prep; adiabatic; coronary; fat; saturation; suppression