Introduction: In most fMRI studies, subject motion is assumed to be restricted to such a small amount that susceptibility-induced distortions can be treated as stationary and independent from motion. However, the ultimate goal of this project is to enable fMRI studies during significant head motion by applying prospective motion correction techniques [1]. In this regime, the motion dependence o...

Respiratory motion is known to degrade image quality in PET imaging. The necessary acquisition time of several minutes per bed position will inevitably lead to a blurring effect due to organ motion. A lot of research has been done with regards to motion correction of PET data. As full-body PET-MRI became available recently, the anatomical data provided by MRI is a promising source of motion inf...

It is well known that some XML elements correspond to objects (in the sense of object-orientation) and others do not. The question we consider in this paper is what benefits we can derive from paying attention to such object semantics, particularly for the problem of keyword queries. Keyword queries against XML data have been studied extensively in recent years, with several lowest-common-ances...

Spiral imaging does not produce apparent flow artifacts. However, it remains sensitive to rapid rigid body motion. In this abstract, a motion correction technique using an orbital navigator “ring” in interleaved spiral imaging is presented. In this technique, a circular k-space trajectory is incorporated into each spiral interleaf. Data inconsistency due to both rotation and translation can be ...

Head motions during functional magnetic resonance imaging (fMRI) impair fMRI data quality and introduce systematic artifacts that can affect interpretation of fMRI results. Electroencephalography (EEG) recordings performed simultaneously with fMRI provide high-temporal-resolution information about ongoing brain activity as well as head movements. Recently, an EEG-assisted retrospective motion c...

PURPOSE Diffusion contrast in diffusion-weighted steady-state free precession magnetic resonance imaging (MRI) is generated through the constructive addition of signal from many coherence pathways. Motion-induced phase causes destructive interference which results in loss of signal magnitude and diffusion contrast. In this work, a three-dimensional (3D) navigator-based real-time correction of t...

Prospective motion correction methods using an optical system, diffusion-weighted prospective acquisition correction, or a free induction decay navigator have recently been applied to correct for motion in diffusion tensor imaging. These methods have some limitations and drawbacks. This article describes a novel technique using a three-dimensional-echo planar imaging navigator, of which the con...