Bernhard Gruber1,2, Maxim Zaitsev1, and Elmar Laistler1
1High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 2Department of Radiology, A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
1High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 2Department of Radiology, A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
We demonstrate a highly flexible coaxial coil
element with integrated on-coil B0 shimming capability that can be
used as a building block for wearable shim+RF coil arrays.
(A) Circuit schematic of the coaxial loop element
with active PIN diode detuning, a tuning LT, and matching circuit. (B)
coaxial loop with interface attached to the phantom. The toroidal chokes of 18
mm diameter with 32 turns of 1 mm diameter magnet wire are soldered to the
shield of the coaxial cable (outer conductor) and on the other side of the
chokes, they are connected with a 1000 pF bypass capacitor, minimizing
fluctuations in the Q-ratio and coil tuning. (C) coaxial cable cross section of
used Molex 047SC-2901, Lisle, IL, USA.
Δ B0 field maps generated by 1 A DC current on the
shield of the coaxial coil in sagittal (through the loop center) and coronal
orientation (approximately 2 cm away from the coaxial loop), measured in a cylindrical
phantom.