Biomedical subjects

P Gonord

Publications and source records attributed to P Gonord.

3 recordsLinked to original sources

PubMed1992

Q optimization of RF inductors for use in NMR probes.

Radiofrequency inductors are important components of many NMR probe circuits, and a high quality factor Q of these inductors is necessary to achieve good signal-to-noise ratios. We have designed high Q inductors using an optimum coil diameter to coil length ratio of the order of 2.54. The latter was calculated from Lorenz's inductance formula for a solenoid and checked experimentally using a series of inductors of various diameters and lengths. The results show good agreement between theory and practice.

Humans↗

PubMed1988

Parallel-plate split-conductor surface coil: analysis and design.

A split-conductor circular parallel-plate resonator with one end shorted to ground can be used to one's advantage as a surface coil for NMR imaging experiments. It can be easily constructed by a printed-circuit method and possesses a relatively high loaded Q with negligible frequency detuning. From the proposed equivalent circuit, an equation was derived that relates the self-resonance frequency of the resonator to the split distance measured from a reference point. An example of a 101-mm-diameter surface coil operating at 26 MHz for 31P in vivo spectroscopy is given to illustrate the concordance between calculated and experimental results. Complementary equations and formulas are also included to assist researchers in designing their own antennas to meet specific requirements.

Magnetic Resonance Imaging↗

PubMed1987

A UHF probe for NMR micro-imaging experiments.

A long solenoid is capable of producing, at least theoretically, a B1 field that is relatively more homogeneous than other known structures. This paper describes the design of a UHF probe incorporating a one-turn solenoid associated with a pair of parallel-plate transmission line feeders and presents a practical example used in a 360-MHz spectrometer for micro-imaging experiments. Numerical evaluation of the solenoid inductance using King's method for direct calculation of elliptic integrals is also included.

Equipment Design↗