Investigation of control scans in pseudo-continuous arterial spin labeling (pCASL): Strategies for improving sensitivity and reliability of pCASL.
To investigate the performance of control scans in pseudo-continuous ASL (pCASL) and propose strategies for improving sensitivity and reliability of pCASL.



The labeling efficiencies of pCASL with conventional control scan and distal control scan were investigated at various radiofrequency (RF) duration/spacing of 0.5/1-2/4 ms, mean slice-selection gradients (GSS) of 1 and 0 mT/m, and total labeling durations of 1.5-3 s, through Bloch equation simulations and in vivo experiments. In addition, the feasibility of three-dimensional (3D) pCASL with the distal control scan and control scan with no RF preparation was demonstrated in a wide brain area, by suppressing the magnetization transfer (MT) effects with high GSSwhile maintaining the GSS/mean GSSratio.



The distal control scan provided pCASL signals approximately 40% higher and more robust to variations in the labeling conditions than those from the conventional control scan. The distal and no RF control scans with high GSSprovided uniform pCASL signals in approximately 8-cm-thick imaging region with MT contributions <10% of the perfusion signals.



pCASL perfusion signals can be enhanced (∼40%) and become more stable by using the distal or no RF control scan, which can be applied in a wide area by increasing GSSwhile maintaining GSS/mean GSS. Magn Reson Med 78:917-929, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Magnetic Resonance Imaging Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
Paul Kyu
PK
Han
Department of Radiology, Seoul National University College of Medicine, Seoul, South Korea.
Seung Hong
SH
Choi
Magnetic Resonance Imaging Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
Sung-Hong
SH
Park
D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D003198:Computer Simulation; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D055420:Perfusion Imaging / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
D013113:Spin Labels
distal control scan; labeling efficiency; perfusion; pseudo-continuous arterial spin labeling