Evaluation of the degree of arteriovenous shunting in intracranial arteriovenous malformations using pseudo-continuous arterial spin labeling magnetic resonance imaging
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Intracranial arteriovenous malformations (AVMs) display venous signals on arterial spin labeling (ASL) magnetic resonance (MR) imaging due to the presence of arteriovenous shunting. Our aim was to quantitatively correlate AVM signal intensity on ASL with the degree of arteriovenous shunting estimated on digital subtraction angiography (DSA) in AVMs.
MR imaging including pseudo-continuous ASL at 3 T and DSA were obtained on the same day in 40 patients with intracranial AVMs. Two reviewers assessed the nidus and venous signal intensities on ASL images to determine the presence of arteriovenous shunting. Interobserver agreement on ASL between the reviewers was determined. ASL signal intensity of the AVM lesion was correlated with AVM size and the time difference between normal and AVM venous transit times measured from the DSA images.
Interobserver agreement between two reviewers for nidus and venous signal intensities was excellent (κ = 0.80 and 1.0, respectively). Interobserver agreement regarding the presence of arteriovenous shunting was perfect (κ = 1.0). AVM signal intensity showed a positive relationship with the time difference between normal and AVM venous transit times (r = 0.638, P < 0.001). AVM signal intensity also demonstrated a positive relationship with AVM size (r = 0.561, P < 0.001).
AVM signal intensity on ASL in patients with AVM correlates well with the degree of early vein opacification on DSA, which corresponds to the degree of arteriovenous shunting.
KeywordsArterial spin labeling (ASL) Arteriovenous malformation (AVM) Arteriovenous shunting Venous signal intensity
Ethical standards and patient consent
We declare that all human and animal studies have been approved by our Institutional Review Board and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. We declare that due to the retrospective nature of this study, informed consent was waived.
Conflict of interest
We declare that we have no conflict of interest.