title: Slice-selective adiabatic magnetization T2-preparation (SAMPA) for efficient T2-weighted imaging at ultrahigh field strengths.
abstract: At high field, T2-weighted (T2w) imaging is limited by transmit field inhomogeneity and increased radiofrequency power deposition. In this work, we introduce SAMPA (Slice-selective Adiabatic Magnetization T2PrepAration) and demonstrate its use for efficient brain T2w imaging at 7 Tesla (T).
  
  
  
  SAMPA was designed by subsampling an optimized B1insensitive rotation (BIR4) waveform with small tip angle linear subpulses. To perform T2w imaging, SAMPA was inserted before a fast gradient echo acquisition. The off-resonance behavior, B1robustness, and slice selectivity of the novel T2preparation module were analyzed using Bloch simulations. The performance of SAMPA for T2w imaging was demonstrated in phantom experiments as well as in the brains of healthy volunteers at 7T.
  
  
  
  Based on simulations, the proposed design operates at peak B1of 15 μT and higher, within a 400 Hz bandwidth. T2values were in strong agreement with spin echo-based T2mapping in phantom experiments. Whole brain, interleaved multislab three-dimensional imaging could be acquired with 0.8 mm3isotropic resolution in 5:36 min per T2weighting.
  
  
  
  Compared with previous adiabatic T2preparation techniques, SAMPA allows for slice-selectivity, which can lead to efficient and robust acquisitions for T2w imaging at high field. Magn Reson Med 76:1741-1749, 2016. © 2015 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Hadrien
authors.initials: H
authors.lastname: Dyvorne
authors.affiliation: Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Priti
authors.initials: P
authors.lastname: Balchandani
mesh_terms: D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: 3D; 7 Tesla; 7T; FLASH; RF pulse; T2 mapping; T2 preparation; adiabatic; multislab; ultrahigh field