Magnetic resonance imaging with adiabatic pulses using a single surface coil for RF transmission and signal detection

In order to overcome the problems that arise from nonuniform B₁, fields, there has been interest in developing pulses that are insensitive to large variations in RF power. Pulses derived from adiabatic passage principles that can execute spin inversion, excitation, and 90°and 180° plane rotations in the presence of B₁, inhomogeneities have recently been described. When driven with optimized modulation functions, these pulses can execute uniform excitation, refocusing, and slice‐selective inversion over a 10‐fold or greater variation in B₁ magnitude. This insensitivity to B₁ strength enables the execution of T 1 − and/or T 2 − weighted spin‐echo imaging experiments using coils, such as the surface coil, with extremely inhomogeneous B₁ profiles. We have successfully acquired images with these pulses at 200 MHz using a single surface coil as the transmitter and receiver. Images of the slice definition, the region over which the excitation and refocusing pulses operate with a surface coil, and brain images obtained with slice planes perpendicular to the plane of the surface coil are presented. Results demonstrate that these pulses can be transmitted with a surface coil to yield high‐quality T 1 − and/or T 2 − weighted images without B₁, artifacts. © 1989 Academic Press, Inc.