A constrained slice-dependent background suppression scheme for simultaneous multislice pseudo-continuous arterial spin labeling

Magn Reson Med. 2018 Jan;79(1):394-400. doi: 10.1002/mrm.26643. Epub 2017 Feb 15.


Purpose: 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 T1 to achieve whole-brain perfusion imaging. Magn Reson Med 79:394-400, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Keywords: arterial spin labeling (ASL); background suppression (BS); controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA); simultaneous multislice (SMS).

MeSH terms

  • Acceleration
  • Adult
  • Algorithms
  • Arteries / diagnostic imaging*
  • Brain / diagnostic imaging
  • Brain Mapping
  • Cerebrovascular Circulation
  • Echo-Planar Imaging*
  • Female
  • Healthy Volunteers
  • Humans
  • Image Enhancement*
  • Image Processing, Computer-Assisted*
  • Imaging, Three-Dimensional
  • Magnetic Resonance Angiography
  • Male
  • Models, Statistical
  • Motion
  • Signal-To-Noise Ratio*
  • Spin Labels
  • Young Adult


  • Spin Labels