Quantitative Functional Arterial Spin Labeling (fASL) MRI--Sensitivity and Reproducibility of Regional CBF Changes Using Pseudo-Continuous ASL Product Sequences

PLoS One. 2015 Jul 14;10(7):e0132929. doi: 10.1371/journal.pone.0132929. eCollection 2015.

Abstract

Arterial spin labeling (ASL) magnetic resonance imaging is increasingly used to quantify task-related brain activation. This study assessed functional ASL (fASL) using pseudo-continuous ASL (pCASL) product sequences from two vendors. By scanning healthy participants twice with each sequence while they performed a motor task, this study assessed functional ASL for 1) its sensitivity to detect task-related cerebral blood flow (CBF) changes, and 2) its reproducibility of resting CBF and absolute CBF changes (delta CBF) in the motor cortex. Whole-brain voxel-wise analyses showed that sensitivity for motor activation was sufficient with each sequence, and comparable between sequences. Reproducibility was assessed with within-subject coefficients of variation (wsCV) and intraclass correlation coefficients (ICC). Reproducibility of resting CBF was reasonably good within (wsCV: 14.1-15.7%; ICC: 0.69-0.77) and between sequences (wsCV: 15.1%; ICC: 0.69). Reproducibility of delta CBF was relatively low, both within (wsCV: 182-297%; ICC: 0.04-0.32) and between sequences (wsCV: 185%; ICC: 0.45), while inter-session variation was low. This may be due to delta CBF's small mean effect (0.77-1.32 mL/100g gray matter/min). In conclusion, fASL seems sufficiently sensitive to detect task-related changes on a group level, with acceptable inter-sequence differences. Resting CBF may provide a consistent baseline to compare task-related activation to, but absolute regional CBF changes are more variable, and should be interpreted cautiously when acquired with two pCASL product sequences.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Arteries / physiology*
  • Cerebrovascular Circulation / physiology*
  • Female
  • Gray Matter / physiology
  • Healthy Volunteers
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Angiography / methods
  • Male
  • Motor Activity / physiology
  • Reproducibility of Results
  • Rest / physiology
  • Sensitivity and Specificity
  • Spin Labels
  • Young Adult

Substances

  • Spin Labels

Grants and funding

This project was financially supported by the Dutch non-governmental organization ‘Stichting Coolsingel’ (Rotterdam, NL). The funder had no role in the study design; data collection, analysis or interpretation; writing of the report; or decision to submit the article for publication (grant no. 179, received by MS; http://www.stichtingcoolsingel.nl/).