<p>Advances in Magnetic Resonance Imaging (MRI) have been made
possible through increased field strengths and innovations in radiofrequency
(RF) coils. With increasing field strengths, unique challenges are presented in
RF coil development, namely the suppression of common-mode currents present
along the shields of the cabling that connect the RF coil to the MR scanner.
These currents can lead to coupling with the coil, resulting in a reduction of
coil sensitivity and signal-to-noise ratio. These currents can induce local
electric fields that beyond a certain level can exceed SAR limits and even
cause patient burns. Several cable trap designs exist to help address this
problem; however, many of the existing designs, such as bazooka cable traps,
are rigid and bulky. This leads to increased overall coil weight and impedes
the flexibility of the cable. Improving upon these designs, a small,
3D-printed, lightweight elliptical cable trap is presented. The unique geometry
makes it invisible to the MR scanner while maintaining significant mutual
inductance that can produce up to 380 Ω on the cable. These structures were
wrapped with stranded wire containing four breaks for tuning capacitors. 60 of
these elliptical cable traps were placed along the length of a 139-cm cable,
replacing the standard 4 bazooka cable traps. The results of B<sub>1</sub>
distortion and heating tests showed that these elliptical baluns improve RF
coil thermodynamic stability, produce less B<sub>1</sub> distortion, and reduce
overall coil weight and bulk compared to a cable with four bazooka traps.
</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/14496570 |
| Date | 29 April 2021 |
| Creators | Jana Vincent (10711377) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | In Copyright |
| Relation | https://figshare.com/articles/thesis/Achieving_Invisible_Balance_Utilizing_Novel_Elliptical_Traps_for_Improved_Radiofrequency_Coil_Thermodynamic_Stability_Minimized_Field_Distortion_and_Common-Mode_Current_Suppression/14496570 |
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