Asymmetric quadrature split birdcage coil for hyperpolarized 3He lung MRI at 1.5T

• Published in: Magnetic resonance in medicine 2008-08, Vol.60 (2), p.431-438
• Main Authors: De Zanche, Nicola, Chhina, Navjeet, Teh, Kevin, Randell, Chris, Pruessmann, Klaas P., Wild, Jim M.
• Format: Article
• Language: English
• Subjects: asymmetric birdcage coil; Computer-Aided Design; Contrast Media; Equipment Design; Equipment Failure Analysis; Helium; helium-3; Humans; hyperpolarized gas imaging; Image Enhancement - instrumentation; Image Enhancement - methods; Isotopes; Lung - anatomy & histology; lung imaging; Magnetic Resonance Imaging - instrumentation; Magnetics - instrumentation; Phantoms, Imaging; Radio frequency coil; Reproducibility of Results; Sensitivity and Specificity; Transducers
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.21664

An asymmetric quadrature birdcage body coil for hyperpolarized (HP) 3He lung imaging at 1.5T is presented. The coil is designed to rest on top of the patient support and be used as a temporary insert in a clinical system. A two‐part construction facilitates patient access and the asymmetric design makes maximal use of available bore space to ensure comfort. Highly homogeneous, circularly polarized RF magnetic fields are produced at 48.5 MHz using a conformal mapping method for the geometrical design, combined with an algebraic method to calculate the individual capacitance values on the birdcage coil's ladder network. Efficiency and isolation from the system's proton body coil are ensured by an integrated RF screen. The design methodology is readily applicable to other field strengths or nuclei. Improvements over existing 3He coils were found in terms of sensitivity and transmit field homogeneity, an important feature in HP MRI. Magn Reson Med 60:431–438, 2008. © 2008 Wiley‐Liss, Inc.