Comprehensive RF safety concept for parallel transmission MR.

Purpose: The goal of this study is to increase patient safety in parallel transmission (pTx) MRI systems. A major concern in these systems is radiofrequency-induced tissue heating, which can be avoided by specific absorption rate (SAR) prediction and SAR monitoring before and during the scan.

Methods: In this novel comprehensive safety concept, the SAR is predicted prior to the scan based on precalculated fields obtained from electromagnetic simulations on different body models.

A new framework for interleaved scanning in cardiovascular MR: Application to image-based respiratory motion correction in coronary MR angiography.

Purpose: To describe a new framework for interleaving scans and demonstrate its usefulness for image-based respiratory motion correction in whole heart coronary MR angiography (CMRA).

Methods: Scan interleaving using the proposed approach was achieved by switching between separately defined, independent scans at arbitrary time points during their execution, using a generic function call. The scan interleaving framework was used to perform scan interleaving for image-based respiratory navigation of CMRA with spiral, radial, and Cartesian echo-planar imaging (EPI) navigator k-space trajectories.

A specific absorption rate prediction concept for parallel transmission MR.

The specific absorption rate (SAR) is a limiting factor in high-field MR. SAR estimation is typically performed by numerical simulations using generic human body models. However, SAR concepts for single-channel radiofrequency transmission cannot be directly applied to multichannel systems.