title: Radiofrequency pulse design with numerical optimization in the Fourier domain.
abstract: OBJECTIVE
  A radiofrequency (RF) pulse design technique is presented that uses iterative constrained minimization to determine Fourier domain coefficients for an optimal time domain RF pulse. The design of new RF pulses is especially beneficial for field strengths of 7.0 T and above, where challenges pertaining to specific absorption rate (SAR) are exacerbated.
  
  
  CONCLUSIONS
  A pair of 90° and 180° spin-echo pulses was designed to lower SAR without the need for a variable slice gradient. The optimized pulses were deployed to a 7.0 T human scanner to demonstrate a reduction in SAR while retaining signal-to-noise (SNR) ratio.
authors.affiliation: Department of Biophysics, The Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
authors.forename: Andrew Michael
authors.initials: AM
authors.lastname: Huettner
authors.affiliation: Department of Biophysics, The Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA. anencka@mcw.edu.|Department of Radiology, The Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA. anencka@mcw.edu.
authors.forename: Andrew Scott
authors.identifier: http://orcid.org/0000-0001-5268-2718
authors.initials: AS
authors.lastname: Nencka
mesh_terms: D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D017352:Echo-Planar Imaging / Q000379:methods*; D005583:Fourier Analysis; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008962:Models, Theoretical; D011846:Radio Waves; D059629:Signal-To-Noise Ratio; D012984:Software
keywords: Diffusion MRI; Echo-planar imaging; Magnetic resonance imaging; Numerical analysis