Traditional neutron tomography allows to reconstruct the attenuation cross section, a measure for the material distribution, at high spatial resolution and non-destructively. However, it does not state anything about the ordering structure of the atoms inside this material. Extending the setup with a second neutron imaging detector, diffracted neutrons from the ordered crystal lattice could be ...

Background CE-MRA following the injection of a gadolinium-based contrast agent (GBCA) bolus is widely used in clinical assessment of vascular dynamics and tissue perfusion (1,2). Although keyhole techniques with an increased number of central k-space updates further improved contrast kinetics information, spatial resolution remains limited. Alternatively applied view sharing approaches also res...

In this paper, we present an iterative algorithm for reconstructing a three-dimensional density function from a set of two dimensional electron microscopy images. By minimizing an energy functional consisting of a fidelity term and a regularization term, an L(2)-gradient flow is derived. The flow is integrated by a finite element method in the spatial direction and an explicit Euler scheme in t...

PURPOSE To evaluate the clinical benefit of using a new iterative reconstruction technique fully integrated on a standard clinical scanner and reconstruction system using a TWIST acquisition for high-resolution dynamic three-dimensional contrast-enhanced MR angiography (CE-MRA). METHODS Low-dose, high-resolution TWIST datasets of 11 patients were reconstructed using both standard GRAPPA-based...

Introduction: Iterative reconstruction techniques provide better image quality and have the potential for reconstructions with lower imaging dose than classical methods in computed tomography (CT). However, the computational speed is major concern for these iterative techniques. The system matrix calculation during the forward- and back projection is one of the most time- cons...

The binary steering process is a heuristic designed to intervene between consecutive steps of a nonbinary iterative image reconstruction algorithm in order to gradually steer the iterates towards a binary solution. We present computational results which show that a strongly overrelaxed simultaneous nonbinary iterative algorithm performs in our experiments better than a strongly underrelaxed seq...

We present a remote sensing observational method for the measurement of the spatio-temporal dynamics of ocean waves. Variational techniques are used to recover a coherent space-time reconstruction of oceanic sea states given stereo video imagery. The stereoscopic reconstruction problem is expressed in a variational optimization framework. There, we design an energy functional whose minimizer is...

We present in this work a comparison among four algorithms for transmission tomography. The algorithms are based on the formalism of POCS (Projection onto Convex Sets): ART (Algebraic Reconstruction Technique), SIRT (Simultaneous Iterative Reconstruction Technique), sequential POCS and parallel POCS. We found that the use of adequate a priori knowledge about the solutions, expressed by convex s...