Cerebral Blood Flow Assessment by Digital Subtraction Angiography

Cerebral vascular disease is responsible for nearly 800 000 hospital admissions annually with a total healthcare cost of $34 billion. Neuro-interventional surgery is at the forefront of fast-response assessment and intervention to assess patients’ health using digital subtraction angiography (DSA). Unfortunately, cerebral blood flow cannot be reliably measured with DSA during intervention. In this study, we introduced a novel inversion-based method to quantify blood flow from DSA intensity profiles. This technique yields absolute volumetric flow rates in major cerebral arteries comparable in accuracy to QMRA measurements. This remarkable outcome was achieved by incorporating patient-specific anatomical data as well as flow physics into the image analysis. The inversion-based flow assessment is a promising approach to render absolute flow measurements with traditional DSA. We also discuss the precision of several methods for assessing cerebral blood flow before and after intervention in DSA were investigated. Angiographic intensity data in four patients with cerebral vascular diseases were analyzed to compute time-to-peak index (TTPi) and relative cerebral angiographic blood flow index (RCABi). Flow indices were compared with quantitative magnetic resonance angiography acquired preand post-intervention. The results suggest that individual intensitybased flow indices do not always reflect blood flow improvements after intervention; twodimensional index maps showed the improvements more robustly.