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INTRODUCTION: Radial sampling of k-space is known to simultaneously provide both high spatial and high temporal resolution. Recently, an optimal radial profile time order based on the Golden Ratio was presented in . We have adopted and modified the idea, with a focus on higher temporal resolution without sacrificing any image quality.
We have suggested a novel method PRESTO-CAN including radial sampling, filtering and reconstruction of k-space data for 3D-plus-time resolved MRI. The angular increment of the profiles was based on the golden ratio, but the number of angular positions N was locked to be a prime number which guaranteed fix angle positions. The time resolution increased… (More)
In this master thesis methods for increasing temporal resolution when reconstructing radially sampled MRI data have been developed and evaluated. This has been done in two steps; first the order in which data is sampled in k-space has been optimized, and second; temporal filters have been developed in order to utilize the high sampling density in central… (More)
BACKGROUND In recent years, there has been a considerable research effort concerning the integration of magnetic resonance imaging (MRI) into the external radiotherapy workflow motivated by the superior soft tissue contrast as compared to computed tomography. Image registration is a necessary step in many applications, e.g. in patient positioning and… (More)
Using dynamic contrast-enhanced MRI (DCE-MRI), it is possible to estimate pharmacokinetic (PK) parameters that convey information about physiological properties, e.g., in tumors. In DCE-MRI, errors propagate in a nontrivial way to the PK parameters. We propose a method based on multivariate linear error propagation to calculate uncertainty maps for the PK… (More)
PURPOSE The purpose of this study was to investigate, using simulations, a method for improved contrast agent (CA) quantification in DCE-MRI. METHODS We developed a maximum likelihood estimator that combines the phase signal in the DCE-MRI image series with an additional CA estimate, e.g. the estimate obtained from magnitude data. A number of simulations… (More)