To develop a fully data‐driven retrospective intrascan motion‐correction framework for volumetric brain MRI at ultrahigh field (7 Tesla) that includes modeling of pose‐dependent changes in polarizing magnetic (B0) fields.
Theory and Methods
Tissue susceptibility induces spatially varying B0 distributions in the head, which change with pose. A physics‐inspired B0 model has been deployed...
This work proposes a novel RF pulse design for parallel transmit (pTx) systems to obtain uniform saturation of semisolid magnetization for magnetization transfer (MT) contrast in the presence of transmit field inhomogeneities. The semisolid magnetization is usually modeled as being purely longitudinal, with the applied field saturating but not rotating its magnetization; thus, standard...
We present in vivo testing of a parallel transmit system intended for interventional MR‐guided cardiac procedures.
The parallel transmit system was connected in‐line with a conventional 1.5 Tesla MRI system to transmit and receive on an 8‐coil array. The system used a current sensor for real‐time feedback to achieve real‐time current control by determining coupling and null modes...
A calibration‐free pulse design method is introduced to alleviate artifacts in clinical routine with parallel transmission at high field, dealing with significant inter‐subject variability, found for instance in the abdomen.
Theory and Methods
From a dual‐transmit 3T scanner, a database of and off‐resonance abdominal maps from 50 subjects was first divided into 3 clusters based...
The Human Connectome Project (HCP) has a 7T component that aims to study the human brain's organization and function with high spatial and temporal resolution fMRI and diffusion-weighted acquisitions. For whole brain applications at 7T, a major weakness however remains the heterogeneity of the radiofrequency transmission field (B1+ ), which prevents from achieving an optimal signal and contrast homogeneously...
The excitation inhomogeneity artifact occurring at 3T in the abdomen can lead to dramatic loss of signal and contrast, thereby hampering diagnosis.
To assess excitation homogeneity and image quality achieved by nonselective prototypical kT‐points pulses, compared to tailored static RF shimming, in clinical routine on a commercial dual‐transmit scanner.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.