Unshielded asymmetric transmit-only and endorectal receive-only radiofrequency coil for 23Na MRI of the prostate at 3 tesla
Document Type
Article
Publication Date
8-1-2015
Journal
Journal of Magnetic Resonance Imaging
Volume
42
Issue
2
First Page
436
Last Page
445
URL with Digital Object Identifier
10.1002/jmri.24798
Abstract
Background To develop and optimize radiofrequency (RF) hardware for the detection of endogenous sodium ( Na) by 3.0 Tesla (T) MRI in the human prostate. Methods A transmit-only receive-only (TORO) RF system of resonators consisting of an unshielded, asymmetric, quadrature birdcage (transmit), and an endorectal (ER), linear, surface (receive) coil were developed and tested on a 3T MRI scanner. Two different ER receivers were constructed; a single-tuned ( Na) and a dual-tuned ( H/ Na). Both receivers were evaluated by the measurements of signal-to-noise ratio (SNR) and B homogeneity. For tissue sodium concentration (TSC) quantification, vials containing known sodium concentrations were incorporated into the ER. The system was used to measure the prostate TSC of three men (age 55-±-5 years) with biopsy-proven prostate cancer. Results B field inhomogeneity of the asymmetric transmitter was estimated to be less than 5%. The mean SNR measured in a region of interest within the prostate using the single-tuned ER coil was 54.0-±-4.6. The mean TSC in the central gland was 60.2-±-5.7 mmol/L and in the peripheral gland was 70.5-±-9.0 mmol/L. Conclusion A TORO system was developed and optimized for Na MRI of the human prostate which showed good sensitivity throughout the prostate for quantitative measurement of TSC. 23 23 1 23 23 1 1