Jugular bulb ASL-MRI hyperintensity and severe internal jugular vein stenosis: a potential pitfall in neuroimaging

Incidental artifactual MRI arterial spin-labeling (ASL-MRI) hyperintense signal at the left jugular bulb (JB-ASL[+]) often creates a neurodiagnostic dilemma because of potential misinterpretation as a dural arteriovenous fistula. JB-ASL(+) likely follows 'benign jugular venous reflux' but an additional contribution to signal genesis owing to styloidogenic jugular venous compression (SJVC) has not been evaluated previously. We studied the link between SJVC percentage stenosis of internal jugular veins (IJVs) and JB-ASL(+) signal intensity by retrospectively reviewing MRIs of 30 JB-ASL(+) patients and 30 age and sex-matched JB-ASL(-) controls. In JB-ASL(+) patients, we found a significantly higher percent increase in ASL-MRI hyperintensity with severe (> 75% IJV stenosis) versus non-severe SJVC (p = 0.026). Thus, in some patients, accentuation of JB-ASL(+) signal conceivably occurs after retrograde trapping of labeled venous blood proximal to a severe SJVC. Presence of severe SJVC represents a novel contributory factor in understanding JB-ASL(+) as a clinically problematic source of neuroimaging misdiagnosis.