Capillary filling analysis by digital subtraction angiography for vertebro-basilar insufficiency.

Vertebro-basilar insufficiency (VBI) is a vague clinical entity including several symptoms such as faintness, dizziness, vertigo. Millikan and Siekert reported a 'syndrome of intermittent insufficiency of basilar arterial system'. But vascular abnormalities responsible for such symptoms are often hardly diagnosed by conventional angiography, because vertebro-basilar artery systems have many kinds of anomalous congenital origins. Conventional angiography gives us arterial informations such as stenosis, occlusion and malformations, but it often fails to reveal capillary perfusions because of its relatively poor density resolution. Digital subtraction angiography (DSA) is considered to have improved density resolution, and it may enable us to detect vascular perfusions more sensitively in the capillary phase. In this study, we evaluated the usefulness of the capillary filling analysis in digital subtraction angiography for diagnosis of VBI.