Investigation of control scans in pseudo-continuous arterial spin labeling (pCASL): Strategies for improving sensitivity and reliability of pCASL

Authors

  • Paul Kyu Han,

    1. Magnetic Resonance Imaging Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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  • Seung Hong Choi,

    1. Department of Radiology, Seoul National University College of Medicine, Seoul, South Korea
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  • Sung-Hong Park

    Corresponding author
    1. Magnetic Resonance Imaging Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
    • Correspondence to: Sung-Hong Park, PhD, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, South Korea 34141. Tel: + 82-42-350-4312; Fax: + 82-42-350-4310; E-mail: sunghongpark@kaist.ac.kr.

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  • This work was supported by the National Research Foundation of Korea (2013R1A1A1061759 and 2013M3A9B2076548) and the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare of South Korea (HI16C1111).

Abstract

Purpose

To investigate the performance of control scans in pseudo-continuous ASL (pCASL) and propose strategies for improving sensitivity and reliability of pCASL.

Methods

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 GSS while maintaining the GSS/mean GSS ratio.

Results

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 GSS provided uniform pCASL signals in approximately 8-cm-thick imaging region with MT contributions <10% of the perfusion signals.

Conclusions

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 GSS while maintaining GSS/mean GSS. Magn Reson Med, 2016. © 2016 International Society for Magnetic Resonance in Medicine.

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