Vincent Gras1, Zaheer Abbas1,
Nadim Jon Shah1,2
1Institute of Neuroscience
& Medicine 4, Medical Imaging Physics, Forschungszentrum Jlich GmbH,
Jlich, Germany; 2Faculty of Medicine, Department of Neurology,
RWTH Aachen University, Aachen, Germany
Mapping of the proton density (PD) is a common MRI application, with interesting perspective in medical research. At 3 Tesla, PD imaging supposes an accurate correction of the sample-dependent RF non-uniformity, which is measured using a dedicated protocol termed B1 mapping. Such measurement is possible if one assumes 1) the linear relationship between flip angle and B1 and 2) the NMR reciprocity principle. From these 2 assumptions, it follows a unique correction scheme. In this work, the accuracy of the correction is evaluated to 2%, setting an upper limit to the precision of the PD measurement achievable with this general approach.
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