University of California

Brenda G Nichols

Mitsuaki A Arakawa

Douglas A Ortendahl

Ernesto Zepeda

Louis T Kircos

Matthias Gyori

An adjustable holder for a magnetic resonance imaging RF surface coil for imaging a part of the body such as the temporomandibular joint. Elements are provided for positioning and securing the RF surface coil at a first predetermined point along a longitudinal axis of the holder and for positioning and securing the RF surface coil at a second predetermined point transverse to the longitudinal axis and at a radial distance R from the longitudinal axis. The preferred embodiment provides orbital movement of the surface coil about the longitudinal axis using a pair of U-shaped runner guides disposed substantially transverse to the longitudinal axis and adjustable clamps in cooperative engagement with the runner guides. The surface coil may be adjusted along a path transverse to the longitudinal axis by way of an adjustable shaft or arm which can be moved inwardly and outwardly, and the surface coil can be pivoted in a step-wise manner using a pivot head having a plurality of equally spaced detents. The pivot head is biased in a direction away from the surface coil and adjustably engages one of the plural detents while rotating about an axis substantially parallel to the longitudinal axis.

Adjustable holders for magnetic reasonance imaging RF surface coil

Frequency tuning and coupling capacitances in MRI RF receive coils are typically realized, at least in part, as reverse biased varactor diodes. During RF tuning of the transmit coil (i.e., so as to achieve resonance and matched impedance conditions), at least some if not all of the varactors associated with the receive coil are forward biased so as to simultaneously maximize detuning of the receive coil to resonant frequencies removed as far as possible from that of the transmitter coil being tuned while also then substantially reducing the Q of the receive coil.

Growing community of inventors

South San Francisco, CA, United States of America

Brenda G Nichols