Introduction: The Borden-Shucart and Cognard scales grade intracranial dural arteriovenous fistulas (dAVFs) based on angiographic features. Recent studies further stratify higher grade dAVFs (those with cortical venous drainage or CVD) based on presenting symptoms; patients presenting with symptomatic CVD (sCVD) carry higher risk of new neurological events than patients with asymptomatic CVD (aCVD). Here, we examine whether MRI T2/FLAIR abnormalities at presentation are associated with higher angiographic grade and/or mode of presentation.
Methods: We retrospectively identified a cohort of patients from two large academic centers (Washington University in St. Louis and Mayo Clinic in Rochester) who had pre-treatment MRIs with T2/FLAIR imaging available for review. MRIs were analyzed by a panel consisting of an experienced vascular neurosurgeon, an experienced interventional neuroradiologist, and an interventional neuroradiology fellow. All were blinded to patient identity, presenting symptoms, and dAVF grade. The angiographic grade and mode of presentation were determined thereafter and correlated with imaging findings.
Results: Seventy-six patients were included. Thirty patients had Borden-Shucart Type 1 dAVFs: 29 without and 1 with equivocal T2/FLAIR abnormalities. Twenty patients had Borden-Shucart Type 2 or 3 dAVFs with aCVD: 17 without and 3 with T2/FLAIR abnormalities. Twenty-six patients had Borden-Shucart Type 2 or 3 dAVFs with sCVD: 4 without, 20 with definite, and 2 with equivocal T2/FLAIR abnormalities. T2/FLAIR abnormalities were strongly associated with high grade dAVFs with sCVD (p < 0.0001, Fisher’s exact test).
Conclusions: T2/FLAIR abnormalities are highly correlated with dAVFs with sCVD, which should be treated aggressively given their poor natural history. Given this strong correlation, the presence of T2/FLAIR changes in dAVF patients with benign presenting symptoms (i.e. those with aCVD) might identify a subset of patients with higher than expected risk. If proven true in natural history studies, the presence of T2/FLAIR changes associated with dAVFs with aCVD would support a more aggressive treatment approach.
Patient Care: Our research highlights an imaging finding that can be useful for the identification of patients with more aggressive intracranial dural arteriovenous fistulas that require more aggressive treatment.
Learning Objectives: By the conclusion of this session participants should be able to:
1) Describe the association between T2/FLAIR MRI findings and presentation of intracranial dAVFs
2) Discuss the value of MRI findings in determining the clinical management of intracranial dAVFs
3) Discuss the potential implications of T2/FLAIR MRI abnormalities in patients with aCVD
References: Borden JA, Wu JK, Shucart WA: A proposed classification for spinal and cranial dural arteriovenous fistulous malformations and implications for treatment. J Neurosurg 82:166-179, 1995.
Cognard C, Gobin YP, Pierot L, Bailly AL, Houdart E, Casasco A, et al: Cerebral dural arteriovenous fistulas: clinical and angiographic correlation with a revised classification of venous drainage. Radiology 194:671-680, 1995.
Strom RG, Botros JA, Refai D, Moran CJ, Cross DT, 3rd, Chicoine MR, et al: Cranial dural arteriovenous fistulae: asymptomatic cortical venous drainage portends less aggressive clinical course. Neurosurgery 64:241-247; discussion 247-248, 2009.