Composite image formation inz-shimmed functional MR imaging

Composite image formation in z-shimmed functional MR imaging.

A challenge in functional magnetic resonance imaging (fMRI) is to develop imaging methods that are highly sensitive to microscopic field inhomogeneities [the blood oxygenation level-dependent (BOLD) effect] and minimally sensitivity to macroscopic fields. z-Shimming compensates for the through-plane dephasing that arises in gradient-echo images due to magnetic field inhomogeneities. To date, an...

Functional MR imaging on an open 1T MR imaging system: exploiting the advantages of an open MR imaging system for functional MR imaging.

BACKGROUND AND PURPOSE Open MR imaging scanners are designed for imaging of specific patient groups that cannot be routinely scanned with conventional MR imaging scanners (eg, patients with obesity and claustrophobia). This study aims to determine whether BOLD sensitivity on an open 1T scanner is adequate for fMRI for diagnostic and research purposes by directly comparing fMRI results with a st...

Efficient MR Image Reconstruction for Compressed MR Imaging

In this paper, we propose an efficient algorithm for MR image reconstruction. The algorithm minimizes a linear combination of three terms corresponding to a least square data fitting, total variation (TV) and L1 norm regularization. This has been shown to be very powerful for the MR image reconstruction. First, we decompose the original problem into L1 and TV norm regularization subproblems res...

Disorders of cortical formation: MR imaging features.

The purpose of this article was to review the embryologic stages of the cerebral cortex, illustrate the classification of disorders of cortical formation, and finally describe the main MR imaging features of these disorders. Disorders of cortical formation are classified according to the embryologic stage of the cerebral cortex at which the abnormality occurred. MR imaging shows diminished cort...

Functional connectivity MR imaging: fact or artifact?