A 7T double-tuned (1H/31P) microstrip surface RF coil for the IMAGO7 MR scanner

Ultra-High Field (UHF) (4-9.4T) Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) are valuable tools in the diagnosis and monitoring of many diseases thanks to the enhanced Signal-to-Noise Ratio (SNR) and spectral/spatial resolution. However, such UHF MR applications require the development and optimization of specially designed Radio Frequency (RF) coils. In this study we report the design, construction, workbench and MR testing of a novel 7T double-tuned (¹H/³¹P) RF surface coil made with microstrip technology. The RF coil is suitable for MRI and MRS human studies of the lower limbs and also of the human head. The double-tuned RF coil was tested at the IMAGO7 Foundation in Pisa (Italy). Ex vivo MR ¹H images and ³¹P spectra obtained with a large size fresh calf veal sample showed an excellent SNR within about 50 mm from the RF surface coil. It is believed that the combined 7T MR ¹H/³¹P will provide benefits in performing clinical follow-up of muscular disorders in young and aging patients. The proposed design can be easily extended to the simultaneous detection of the ¹H and other low-gamma nuclei, such as ⁷Li, ¹¹B, ¹³C, ¹⁷O, ²³Na.