Tomographic reconstruction of homogeneous objects using multi-step ART

When for example a blood flow is measured by ultrasound Doppler tomography, part of the received data can be modelled as the Radon transform of the region of reflecting particles. The reconstruction problem thus consists of determining a homogeneous object (that is to determine a function only attaining the values 0 and 1) from Radon transform data. The standard inversion method for the Radon transform could be used, however, they do not explicitly use the fact that the function to be reconstructed is binary, in which case the reconstruction procedure ought to be less sensitive to noise. Here we develop an algorithm that use the a priori information to make reliable reconstructions even in the presence of severe noise.