Estimating perfusion using X-ray angiography

In this paper we present a method for extraction of functional information from a time-sequence of X-ray angiographic images. By observing contrast agent propagation profile in a region of the angiogram one can calculate a number of parameters of that profile. Each parameter can be used to construct a parametric image of the imaged area. Such parametric images present a functional rather than morphological aspect of the tissue. The most important functional parameter is perfusion. Perfusion is defined as a blood flow at the capillary level and is commonly used to detect ischemic areas. Perfusion CT and perfusion MRI (pMRI) modalities have commonly been used to extract perfusion data. In this paper, a new method for calculation of perfusion from the contrast agent profile of a sequence of X-ray angiograms is presented. The method utilizes Wiener filtering for denoising of time signals. The experimental results are computed on a sequence of cerebral angiograms.