Three‐line microstrip array for whole‐body mri system at 7 t

Abstract

This paper proposes the use of a triple‐line microstrip array for transmitting a magnetic field (|B1+|) into the whole body for magnetic resonance applications at ultra‐high field strength, such as 7 T. We explored some technologies that can potentially be applied for whole‐body 7 T magnetic resonance imaging, as there is ongoing research on this topic. The triple‐line microstrip transmission line (t‐MTL) array consists of 32 channels. Each channel has a t‐MTL, comprising a main conductor line and two adjacent coupled lines. The adjacent lines are not connected directly to the source. This configuration resulted in increased intensity and a centered |B1+|‐field. We compared the proposed structure and some reference radiofrequency (RF) transmitters, such as a patch antenna, using a magnet bore as a waveguide and a whole‐body birdcage coil. We evaluated the performance of the t‐MTL using cylindrical phantoms. We computed the |B1+ |‐field from each RF transmitter inside a 3D human model containing more than 200 tissues. We compared their uniformity and field intensity and proposed a t‐MTL array that yielded better performance. The proposed design also showed a lower specific absorption rate compared with a patch antenna.