Fast phase-modulated B1+ mapping in the low flip-angle regime
نویسندگان
چکیده
Introduction and purpose: In high-field MRI phased transmit arrays are used to mitigate RF issues, e.g. optimizing the inhomogeneous B1 field using spatially tailored RF pulses played out by such an array. In order to design the RF pulses that produce the desired excitation field, the B1 field per coil must be mapped. Ideally, these B1 mapping techniques are fast and have a low SAR deposition. However, most of the contemporary B1 mapping techniques require large flip angles [1,2] and are therefore accompanied by relatively high SAR values. As a consequence, lengthy acquisition times are needed to stay within SAR limits. In this abstract we describe a fast method to measure the B1 field per coil in the low flipangle regime, using phase modulated 3D low flip angle (PMLF) GRE images.
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