U-Shaped Ladder TEM-Coil Structure with Truncated Sensitivity Profile in Z-Direction for High Field MRI

Christoph Leussler¹, Daniel Wirtz¹, Jan Hendrik Wuelbern¹, Peter Vernickel¹, Peter Forthmann¹

TEM-coils come with a sensitivity profile and field-of view (FOV) that is largely extended in the z-direction compared with birdcage coils (BC). The excess z-FOV leads to safety issues with respect to the specific absorption rate (SAR). We present a novel TEM coil with modified geometry, which has the strip section of each TEM coil element extended laterally at both ends before connecting to the RF screen. Each of these lateral extensions has been found to produce transversal B1 field at the isocenter resulting in a steeper sensitivity profile and thus partially compensating the drawback of a traditional TEM element.