Magma (New York, N.Y.)
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Magma (New York, N.Y.) · Jun 2012
Highly accelerated PSF-mapping for EPI distortion correction with improved fidelity.
This study presents an improved point-spread-function (PSF) mapping-based distortion correction method and accelerated PSF acquisition for distortion correction in EPI without loss of quality or reliability compared to full encoding. ⋯ The proposed EPI-PSF-based distortion correction improves correction of EPI and accelerates PSF reference data acquisition and computation.
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Magma (New York, N.Y.) · Jun 2012
Local SAR management by RF shimming: a simulation study with multiple human body models.
Parallel transmission facilitates a relatively direct control of the RF transmit field. This is usually applied to improve the RF field homogeneity but might also allow a reduction of the specific absorption rate (SAR) to increase freedom in sequence design for high-field MRI. However, predicting the local SAR is challenging as it depends not only on the multi-channel drive but also on the individual patient. ⋯ Parallel transmission can become an important tool to control and manage the local SAR in the human body. The practical use of local SAR constraints is feasible with consistent results for a variety of body models.