Radiofrequency coils for magnetic resonance applications: theory, design, and evaluation.
Magnetic resonance imaging and magnetic resonance spectroscopy are noninvasive diagnostic techniques based on the phenomenon of nuclear magnetic resonance. Radiofrequency coils are key components in both the transmission and receiving phases of magnetic resonance systems. Transmitter coils have to produce a highly homogeneous alternating field in a wide field of view, whereas receiver coils have to maximize signal detection while minimizing noise. Development of modern magnetic resonance coils often is based on numerical methods for simulating and predicting coil performance. Numerical methods allows the behavior of the coil in the presence of realistic loads to be simulated and the coil's efficiency at high magnetic fields to be investigated. After being built, coils have to be characterized in the laboratory to optimize their setting and performance by extracting several quality indices. Successively, coils performance has to be evaluated in a scanner using standardized image quality parameters with phantom and human experiments. This article reviews the principles of radiofrequency coils, coil performance parameters, and their estimation methods using simulations, workbench, and magnetic resonance experiments. Finally, an overview of future developments in radiofrequency coils technology is included.
Institute of Clinical Physiology, National Council of Research, Pisa, Italy; Fondazione G. Monasterio CNR - Regione Toscana, Pisa, Italy.
Giulio
G
Giovannetti
Institute of Clinical Physiology, National Council of Research, Pisa, Italy; Fondazione G. Monasterio CNR - Regione Toscana, Pisa, Italy.
Valentina
V
Hartwig
Institute of Clinical Physiology, National Council of Research, Pisa, Italy; Fondazione G. Monasterio CNR - Regione Toscana, Pisa, Italy.
Vincenzo
V
Positano
Institute of Clinical Physiology, National Council of Research, Pisa, Italy; Department of Information Engineering, University of Pisa, Pisa, Italy.
Nicola
N
Vanello
D004867:Equipment Design; D020342:Finite Element Analysis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D059629:Signal-To-Noise Ratio