Design and testing of a 24-channel head coil for MR imaging at 3 T.

PURPOSE: To offer the new head coil option (with a lower channel count) of an RF coil array that provides comparable performance to the commercial 32-channel head coil.

METHODS: The coil system comprised an upper shield (ten channels) and bottom section (fourteen channels). Signal-to-noise ratio (SNR) values for 2D unaccelerated imaging and the g-factor with an acceleration factor of 2-4 were evaluated in a phantom study. SNR performance and human brain and intracranial vessel wall imaging were conducted as part of the in vivo study. Both studies were conducted using the commercial head coil on the Siemens Tim Trio 3 T system for comparison.

RESULTS: In the phantom study, the new head coil had an 8% higher SNR than the commercial head coil and demonstrated less than a 1% difference in the g-factor with the acceleration factor 2-4 in the right-to-left and anterior-to-posterior directions. In the in vivo study, the performance matched the results seen in the phantom study and showed high reproducibility in several human experiments. Structural images of the brain and intracranial vessel wall with an isotropic spatial resolution of 0.5 mm can be acquired with the new head coil.

CONCLUSION: This study demonstrates that the new head coil is capable of providing good SNR performance in both phantom and human experiments, can achieve similar acceleration ability compared to the commercial head coil, and is capable of obtaining brain and intracranial vessel wall images.