Intracranial arteriovenous malformation: Semiquantitative analysis of arterial spin labeling magnetic resonance imaging in correlation with digital subtraction angiography

Abstract

Objectives: Intracranial arteriovenous malformations (AVMs) display venosinus signals on arterial spin labeling (ASL) due to the presence of arteriovenous shunting. Our aim was to quantitatively correlate venosinus signal intensity on ASL with digital subtraction angiography (DSA) in patients with intracranial AVMs. Materials and Methods: Magnetic resonance (MR) imaging and DSA were obtained on the same day in 40 patients (25, previously untreated

15, previously treated) with intracranial AVMs. Two reviewers assessed the ASL images based on identifying nidus, venous, and sinus signal intensities to determine the presence of arteriovenous shunting. Interobserver agreement on ASL between the reviewers was determined. The signal intensity measured from the veins or sinus on ASL was correlated with the time difference between normal and AVM venous transit times measured from the DSA images. Venosinus signal intensity was also correlated with AVM size. Results: Interobserver agreement between the two reviewers for nidus, venous and sinus signal intensity was moderate-to-excellent (κ = 0.44, 0.66, and 0.83, respectively). Interobserver agreement with respect to the presence of arteriovenous shunting was good (κ = 0.79). Sinus signal intensity showed a positive relationship with the time difference between normal and AVM venous transit times (P = 0.008). Sinus signal intensity also demonstrated a strong positive relationship with AVM size (P < 0.0001). Conclusion: Venosinus signal intensity on ASL is useful in identifying intracranial arteriovenous shunts. Sinus signal intensity measured on ASL correlates well with the degree of early vein opacification on DSA.