IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Longitudinal gradient coils with optimized uniformity for restricted volumes
Autor/es:
JAVIER A. ROMERO; GABRIELA A. DOMINGUEZ; ESTEBAN ANOARDO
Reunión:
Conferencia; 9th Conference on Fast Field-Cycling NMR Relaxometry; 2015
Resumen:
Differentmethods have been considered for the calculation and optimization of cylindricalgradient coils1-3. The search for efficient coils with compactdesign has attracted the attention of different groups in the past4-6.Here we deal with the design of  longitudinalgradient coils with improved usage of the gradient field respect to the netcoil volume.  An optimization algorithm wasimplemented in order to calculate the current distribution within a cylindricalsymmetry. The algorithm was first tested by considering single-current gradientcoils. The method was validated by comparing the calculated coil withmeasurements performed in a model prototype. Then a multiple-coil arrayconsisting of independent elements (fed by independent currents) was analyzedusing the same algorithm. This architecture offers an excellent magnetic fieldlinearity if  confrontedwith other experimentally validated designs available in the literature7,8. The generated gradient field uses a higher fractionof the inner coil volume, which makes for a compact design. The fraction of thecoil volume producing a linear gradient (and consequently the coil efficiency)can be adjusted or switched between different configurations. In addition, thecoil can also be used for the screening of unwanted longitudinal magneticcomponents. [1]- R. Turner. J. Phys. E: Sci. Instrum. 1988, 21, 948-952.[2]- S. Crozier; D. M.Doddrell. J. Magn. Reson. 1993, A103, 354-357.[3]- R. Turner. Magn. Reson. Imag. 1993, 11, 903-920.[4]- B. A. Chronik; B. K.Rutt. Magn. Reson. Med. 1998, 39, 270-278.[5]- D. Tomasi. Magn. Reson. Med. 2001, 45, 505-512.[6]- V. Vegh; H. Zhao; I.M. Brereton; G. J. Galloway; D. M. Doddrell. Concept Magn. Reson. 2006,29B, 62-74.[7]- R. Bowtell; P. Robyr. J. Magn. Reson. 1998,131, 286-294.[8]- R. Lemdiasov; R. Ludwing. Concept Magn.Reson. B. 2005, 26, 67-80.