TABLE 2:

Summary of Strategies to Differentiate Dural Arteriovenous Fistula From Internal Jugular Reflux

Strategy	MRI-MRA Sequences	Dural Arteriovenous Fistula	Physiologic Internal Jugular Vein Reflux
Structural
Assess arterial system for abnormality	Time-of-flight MRA	Enlarged external carotid artery branches; particular attention to ascending pharyngeal-neuromeningeal trunk)	Normal-caliber external carotid artery branches
Assess venous system for abnormality	Contrast-enhanced T1-weighted, susceptibility-weighted imaging	Evidence of venous sinus thrombosis	Patent venous sinuses
		Abnormal oxygenated blood in veins	Normal deoxygenated blood in veins (T2*)
Functional
Assess for physiologic evidence of shunting	TRICKS, T2-weighted FLAIR	Early (arterial phase) opacification of veins with contrast material	Venous opacification normal or delayed
	Susceptibility-weighted imaging	Venous congestive pattern of cerebral edema	No evidence of parenchymal congestion or edema

Note—TRICKS = time-resolved imaging of contrast kinetics.