title: Whole-brain perfusion imaging with balanced steady-state free precession arterial spin labeling.
abstract: Recently, balanced steady-state free precession (bSSFP) readout has been proposed for arterial spin labeling (ASL) perfusion imaging to reduce susceptibility artifacts at a relatively high spatial resolution and signal-to-noise ratio (SNR). However, the main limitation of bSSFP-ASL is the low spatial coverage. In this work, methods to increase the spatial coverage of bSSFP-ASL are proposed for distortion-free, high-resolution, whole-brain perfusion imaging. Three strategies of (i) segmentation, (ii) compressed sensing (CS) and (iii) a hybrid approach combining the two methods were tested to increase the spatial coverage of pseudo-continuous ASL (pCASL) with three-dimensional bSSFP readout. The spatial coverage was increased by factors of two, four and six using each of the three approaches, whilst maintaining the same total scan time (5.3 min). The number of segments and/or CS acceleration rate (R) correspondingly increased to maintain the same bSSFP readout time (1.2 s). The segmentation approach allowed whole-brain perfusion imaging for pCASL-bSSFP with no penalty in SNR and/or total scan time. The CS approach increased the spatial coverage of pCASL-bSSFP whilst maintaining the temporal resolution, with minimal impact on the image quality. The hybrid approach provided compromised effects between the two methods. Balanced SSFP-based ASL allows the acquisition of perfusion images with wide spatial coverage, high spatial resolution and SNR, and reduced susceptibility artifacts, and thus may become a good choice for clinical and neurological studies. Copyright © 2015 John Wiley & Sons, Ltd.
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
authors.forename: Paul Kyu
authors.initials: PK
authors.lastname: Han
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Ye
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon, South Korea.
authors.forename: Eung Yeop
authors.initials: EY
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
authors.forename: Sung-Hong
authors.initials: SH
authors.lastname: Park
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D010477:Perfusion; D059629:Signal-To-Noise Ratio; D013113:Spin Labels; D055815:Young Adult
chemical_list: D013113:Spin Labels
keywords: arterial spin labeling; balanced steady-state free precession; compressed sensing; high resolution; perfusion; segmented acquisition; whole brain