The twisted solenoid RF phase gradient transmit coil for TRASE imaging

Hongwei Sun; Stephanie Yong; Jonathan C Sharp

doi:10.1016/j.jmr.2018.12.015

The twisted solenoid RF phase gradient transmit coil for TRASE imaging

J Magn Reson. 2019 Feb:299:135-150. doi: 10.1016/j.jmr.2018.12.015. Epub 2018 Dec 17.

Authors

Hongwei Sun¹, Stephanie Yong¹, Jonathan C Sharp²

Affiliations

¹ Department of Oncology, University of Alberta, Edmonton, Alberta, Canada.
² Department of Oncology, University of Alberta, Edmonton, Alberta, Canada. Electronic address: jcsharp@ualberta.ca.

PMID: 30594884
DOI: 10.1016/j.jmr.2018.12.015

Abstract

TRASE is an MRI k-space encoding method that uses radio-frequency (RF or B₁) transmit phase gradient fields to achieve millimeter-level spatial resolution. Image quality is critically dependent upon the efficient generation of B₁ fields with uniform magnitude and strong phase gradients. We present the design of a new family of phase gradient transmit coil based upon a solenoid twisted about a transverse axis. This design has many attractive geometric, electrical and magnetic characteristics, including the capability to spatially encode in the direction of the main static B₀ field without obstructing access to the bore. Analytical, numerical simulation and experimental results are presented, including demonstration of 1-dimensional TRASE encoding without the use of PIN diode switches. Twisted solenoid coils significantly expand the capabilities of TRASE MRI.

Keywords: Phase gradient; RF coil; TRASE; k-space.

Publication types

Research Support, Non-U.S. Gov't