Radiology, Vol 157, 449-452, Copyright © 1985 by Radiological Society of North America
Improved surface coil imaging in MR: decoupling of the excitation and receiver coils
EB Boskamp
We obtained magnetic resonance images with good sensitivity and radio
frequency (RF) uniformity using separate transmitter and receiver coils.
The excitation, namely, the rotation of the magnetization vector into a
plane perpendicular to the magnetic field, was done by applying a
homogeneous RF magnetic field produced by a large saddle-shaped coil.
Surface coils were used for detection only. Because two coils that operated
on the same resonance frequency were used, a coupling problem developed.
This problem, which involved inhomogeneity of the RF magnetic field caused
by the large current induced in the surface coil during excitation, could
only be solved by minimizing the mutual inductance or maximizing the
impedance of the surface coil resonance circuit during excitation. We were
able to solve this problem using an electronic detuning method.
