Arterial spin labeling MR imaging aids to identify cortical venous drainage of dural arteriovenous fistulas

Abstract

Cortical venous drainage (CVD) increases the probability of intracranial hemorrhage and mortality rate of dural arteriovenous fistulas (DAVF). Although digital subtraction angiography (DSA) is the most accurate method to determine CVD in DAVFs, this modality has limitations due to its invasive nature and radiation issues. The purpose of this study was to evaluate the diagnostic utility of arterial spin-labeling perfusion-weighted images (ASL-PWI) to identify CVD in patients with DAVF.The Institutional Review Board of our hospital approved this retrospective study. ASL-PWI features of 22 patients with DAVF were retrospectively reviewed for the presence of bright signal intensity in cortical veins and brain parenchyma. DAVF with bright signal intensity in cortical veins and/or brain parenchyma was regarded as having CVD. Using DSA as a reference standard, sensitivity, specificity, positive predictive value, and negative predictive value of ASL-PWI for detecting CVD were calculated.Based on DSA features, 11 (11/22, 50%) patients were classified as having "aggressive" pattern with CVD. Eleven (11/22, 50%) patients also showed bright signal intensity in cortical veins (9/22, 41%) and/or brain parenchyma (4/22, 18%) on ASL-PWI. The 11 patients who had "Aggressive" pattern on DSA were the same 11 patients who were classified as having "aggressive" pattern on ASL-PWI. ASL-PWI showed perfect diagnostic performance for identifying CVD with sensitivity, specificity, positive predictive value, and negative predictive value of 100% for all.Thus, ASL-PWI could be used as a noninvasive mean to predict the presence of CVD in patients with DAVFs. It has the potential as a screening tool to evaluate DAVF prior to invasive DSA.

Figure 1

A 53-year-old man presented with left-sided tinnitus. (A) ASL-PWI shows bright signal intensity apparent in the left sigmoid sinus at distal to DAVF (arrow). However, bright signal intensity in the cortical vein is not definite on ASL-PWI. (B and C) DSA images reveal early hypervascular staining in the left sigmoid sinus and internal jugular vein (arrows) and DAVF (arrowheads). However, CVD is not definite on DSA. ASL-PWI = arterial spin-labeling perfusion-weighted image, CVD = cortical venous drainage, DAVF = dural arteriovenous fistula, DSA = digital subtraction angiography.

Figure 2

A 55-year-old woman presented with gait disturbance. (A) ASL-PWI shows bright signal intensity apparent in the superior sagittal sinus just proximal to torcula (arrow). Bright signal intensities in the brain parenchyma are also shown (arrowheads). (B) ASL-PWI at vertex level shows bright signal intensities in the superior sagittal sinus (arrow) implying retrograde drainage and bright signal intensity in the cortical veins (asterisks) implying presence of CVD. (C and D) DSA images reveal early hypervascular staining in the superior sagittal sinus and straight sinus (arrows) and DAVF at torcula (arrowhead). CVD is also shown on DSA (asterisks). ASL-PWI = arterial spin-labeling perfusion-weighted image, CVD = cortical venous drainage, DAVF = dural arteriovenous fistula, DSA = digital subtraction angiography.

Figure 3

A 79-year-old woman presented with altered mentality. (A) ASL-PWI shows bright signal intensity apparent in the left transverse sinus just proximal to left transverse sinus-sigmoid sinus junction (arrow). Bright signal intensity is also apparent in the left transverse sinus around the midline (arrowhead) implying retrograde draining. (B) ASL-PWI shows bright signal intensities in the brain parenchyma (arrows) implying presence of CVD. However, bright signal intensity in the cortical vein is not definite on ASL-PWI. (C and D) DSA images reveal DAVF at the left transverse sinus-sigmoid sinus junction (arrowheads). CVD is also shown on DSA (asterisks). ASL-PWI = arterial spin-labeling perfusion-weighted image, CVD = cortical venous drainage, DAVF = dural arteriovenous fistula, DSA = digital subtraction angiography.