title: A constrained slice-dependent background suppression scheme for simultaneous multislice pseudo-continuous arterial spin labeling.
abstract: OBJECTIVE
  To present a constrained slice-dependent (CSD) background-suppression (BS) scheme in 2D arterial spin labeling (ASL) using simultaneous multislice acquisition with blipped-CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration).
  
  
  METHODS
  Background suppression for 2D acquisition is challenging because of the multiple nulling points required for sequential slice readout. Constrained slice-dependent BS exploits the simultaneous multislice technique to reduce the readout duration, and uses slice-dependent premodulation pulses to achieve BS across slice groups. The proposed scheme was evaluated by in vivo brain experiments at 3 Tesla with multiband acceleration factors up to four. The utility of CSD BS was demonstrated through comparison against standard 2D acquisitions as well as 3D-BS pseudo-continuous ASL (pCASL).
  
  
  RESULTS
  An average of 95% background signal reduction was achieved with CSD BS. As a result, the temporal signal-to-noise ratio (SNR) increased 48.2/39.9/36.9/36.0% and spatial SNR increased 132.5/80.0/63.5/54.2 in CSD-BS MB-1/2/3/4 scans, respectively. Whole-brain coverage was achievable with CSD-BS pCASL with MB-4, which yielded comparable spatial SNR as 3D BS pCASL.
  
  
  CONCLUSIONS
  The proposed CSD-BS scheme for 2D-SMS pCASL offers a promising approach for effective suppression of background signals across a wide range of T1to achieve whole-brain perfusion imaging. Magn Reson Med 79:394-400, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Soutern California, Los Angeles, California, USA.
authors.forename: Xingfeng
authors.initials: X
authors.lastname: Shao
authors.affiliation: MR Clinical Science, Philips Healthcare, Gainesville, Florida, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Steen
authors.initials: S
authors.lastname: Moeller
authors.affiliation: Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Soutern California, Los Angeles, California, USA.
authors.forename: Danny J J
authors.initials: DJJ
authors.lastname: Wang
mesh_terms: D000054:Acceleration; D000328:Adult; D000465:Algorithms; D001158:Arteries / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging; D001931:Brain Mapping; D002560:Cerebrovascular Circulation; D017352:Echo-Planar Imaging; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography; D008297:Male; D015233:Models, Statistical; D009038:Motion; D059629:Signal-To-Noise Ratio; D013113:Spin Labels; D055815:Young Adult
chemical_list: D013113:Spin Labels
keywords: arterial spin labeling (ASL); background suppression (BS); controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA); simultaneous multislice (SMS)