Design and test of a double-nuclear RF coil for 1 H MRI and 13 C MRSI at 7 T

Abstract

RF coil operation at the ultrahigh field of 7T is fraught with technical challenges that limit the advancement of novel human in vivo applications at 7T. In this work, a hybrid technique combining a microstrip transmission line and a lumped-element L-C loop coil to form a double-nuclear RF coil for proton magnetic resonance imaging and carbon magnetic resonance spectroscopy at 7T was proposed and investigated. Network analysis revealed a high Q-factor and excellent decoupling between the coils. Proton images and localized carbon spectra were acquired with high sensitivity. The successful testing of this novel double-nuclear coil demonstrates the feasibility of this hybrid design for double-nuclear MR imaging and spectroscopy studies at the ultrahigh field of 7T.

Radiofrequency Coil Design for in vivo Sodium Magnetic Resonance Imaging of Mouse Kidney at 9.4T

“…In fact, this design technique can also be used to construct coils for imaging of other nuclei such as 13 C and 31 P through adjusting variable capacitors. Because the resonance frequency of sodium is similar to that of carbon (sodium, 105.8 MHz; carbon, 100.6 MHz), 13 C signal can also be detected by using a modulating trimmer (14,15). This work is the first step to obtain in vivo sodium images at 9.4T.…”

Acquisition strategies for spatially resolved magnetic resonance detection of hyperpolarized nuclei

“…For example, at 3 T, 128 MHz for 1 H is sample noise dominated, whereas 32 MHz for 13 C has relatively more noise contribution from the coil [52], meaning improved coil design can be more impactful. Dual resonance coils are also available for 1 H and 13 C, 23 Na, or 31 P, [48, [53][54][55][56][57][58], which are useful for heteronuclear 1 H- 13 C decoupling [48,59] and polarization transfer applications, which involve simultaneous transmission on multiple frequency channels. Triple resonance coils [60,61] can also be helpful for B 1 calibration of hyperpolarized compounds containing 13 C by using signal from natural abundance 23 Na, because their Larmor frequencies are similar.…”

Scalable and modular 8‐channel transmit and 8‐channel flexible receive coil array for 19F MRI of large animals

“…21 Geometric decoupling can also be used in double-tuned coils. [26][27][28][29][30] Although there are many examples of 19 F coils for small animal measurements, only a few designs were demonstrated for human and large animal applications: 19 F knee MRI at 7 T, 31 human liver MRS, 32 and lung MRI 33 at 1.5 T, pig at 3 T using a dual-tuned transmit (Tx), and a 19 F-surface loop coil. 34 In general, dual-tuned 19 F/ 1 H coils show an inferior performance compared with mononuclear coil designs.…”

“…Counter‐rotating currents can cause significant loss in magnetic field intensity of the coils 21 . Geometric decoupling can also be used in double‐tuned coils 26–30 . Although there are many examples of 19 F coils for small animal measurements, only a few designs were demonstrated for human and large animal applications: 19 F knee MRI at 7 T, 31 human liver MRS, 32 and lung MRI 33 at 1.5 T, pig at 3 T using a dual‐tuned transmit (Tx), and a 19 F‐surface loop coil 34 .…”