Resting-state functional magnetic resonance imaging (RS-fMRI) is used to investigate brain functional connectivity at rest. However, noise from human physiological motion is an unresolved problem associated with this technique. Following the unexpected previous result that group differences in head motion between control and patient groups caused group differences in the resting-state network w...

Spatial frequency domain imaging (SFDI) is a noncontact and wide-field optical imaging technology currently being used to study the optical properties and chromophore concentrations of in vivo skin including skin lesions of various types. Part of the challenge of developing a clinically deployable SFDI system is related to the development of effective motion compensation strategies, which in tu...

PURPOSE To develop a flexible image navigator for 3D coronary MR angiography that allows respiratory motion of variable complexity to be compensated for on different temporal scales. METHODS A two-dimensional (2D) golden radial image navigator is proposed; translational motion is compensated for on a beat-to-beat basis, and residual affine motion is compensated for on a bin-to-bin basis in a ...

When patients move during an MRI examination, severe artifacts arise in the reconstructed image and motion correction is therefore often desired. An in-plane motion correction algorithm suitable for PRESTO-CAN, a new 3D functional MRI method where sampling of k-space is radial in kx-direction and kz-direction and Cartesian in ky-direction, was implemented in this thesis work. Rotation and trans...

Introduction Patient motion is a significant problem for MR imaging. Spiral Projection Imaging (SPI) is a 3-D imaging sequence, which provides enough data to deduce all six degrees of freedom of bulk motion [1]. Motion correction has been successfully demonstrated for quadrature coil data (both real and synthetic), by comparing data from individual planes [2,3] (Fig. 1). The extension to multi-...

BACKGROUND Respiratory motion in positron emission tomography (PET) is an unavoidable source of error in the measurement of tracer uptake, lesion position and lesion size. The introduction of PET-MR dual modality scanners opens a new avenue for addressing this issue. Motion models offer a way to estimate motion using a reduced number of parameters. This can be beneficial for estimating motion f...

The objectives of this study were to use computer-generated phantoms containing real subject motion to: (1) compare the sensitivity of four commonly used fMRI software packages and (2) compare the sensitivity of three statistical analysis strategies with respect to motion correction. The results suggest that all four packages perform similarly in fMRI statistical analysis with SPM2 having sligh...

INTRODUCTION: In contrast-enhanced MRI, medical diagnosis is often compromised by the motion, the need for registration and the difficulty of sustaining a breath-hold. A previously published motion correction algorithm GRICS (Generalized Reconstruction by Inversion of Coupled Systems) [1] has proven to correct for motion artefacts successfully in images acquired with a wide set of sequences, th...

PURPOSE Subject motion can severely degrade MR images. A retrospective motion correction algorithm, Gradient-based motion correction, which significantly reduces ghosting and blurring artifacts due to subject motion was proposed. The technique uses the raw data of standard imaging sequences; no sequence modifications or additional equipment such as tracking devices are required. Rigid motion is...

The basic preprocessing pipeline contains two new methods: Motion Adjustment and Artifact Repair. The pipeline separates the motion adjustment and artifact removal algorithms into the preprocessing before GLM estimation, thus, motion regressors are not needed in the design matrix. The intermediate data can be reviewed at any step using the Contrast Movie, the RMS image, or plots of single voxel...