Purpose: To characterize the performance of a newly developed highly flexible link resonator structure multi element RF coil for MR simulation of patients undergoing radiation therapy of the head and neck and to compare its performance against an FDA approved RF coil designed for the same anatomic site and purpose.
Methods: A humanoid phantom simulating the head, neck and shoulders was constructed and filled with a 50/50 mixture of polyvinyl chloride and softening agent (Lurecraft, Orland, IN). Contiguous 2D coronal Tâ‚?-weighted spin echo images were acquired with the prototype and FDA approved RF coils. Signal-to-noise ratio (SNR) images were generated by dividing pixel intensity values by the standard deviation of a slice which included air only. A total of three separate combinations were tested and included; 1) 22 channel prototype and 8 active element coil set imbedded within a custom built immobilization frame in which all elements consisted of the same 110 mm diameter link resonator coil loop, 2) 22 channel prototype and FDA-approved 8 element conventional array, and 3) 30 channel FDA approved RF conventional coil array set.
Results: The mean SNR within the phantom volume for coil sets 1, 2 and 3 was 192, 179, and 162 respectively. Bonferroni pair wise comparison one-way repeated measures analysis of variance (ANOVA) mean SNR per slice coil sets 1 & 2 were statistically significantly larger (p < 0.05) than set 3. A second image metric - the product of image uniformity and SNR - versus image slice demonstrated similar statistically significant differences.
Conclusion: This work demonstrates that improved image quality can be achieved when employing multichannel RF coil designs using recently developed link resonant structures. This is due to both the performance of the coil elements in combination as well as their light weight and highly flexible and therefore conformal nature.