A genetic algorithm approach to the design of split coil magnets for MRI

Abstract

Absrrmf -Innovntive,open magnet designs for Magnetic Resonance Imaging (MRI) of p r t s of hiimmn body hnve been recently proposed. 'I'lisse open configuritlons require notrl)le skill in the design phase to obtain sntisfnctory perfnrninnre i n terms of compnctness niid field homogenelty: optimization techniques thus seems adequate to m i s t the designer of such devices. A novel o~itinilxation sclicmc, based on n gciietlc nlgorithm (CA) hms been Implcmctited fnr the resolution nf this problem, Tlic G h seems well suited For this mpplicitlons thanks to Its abillty in exploring the whole desip parameters sprcr, iiot bceii implemented, namely tlonting point pnrnmctrr representation, lntrodiiction of R direciionn! miitfitlon opcrntor and ndiptive probability of operators rctioii.

Globally optimal superconducting magnets Part II: Symmetric MSE coil arrangement

“…A number of advancements in design have seen the development of improved and cheaper technologies in magnet construction and performance [2][3][4][5][6][7][8][9], which provide clear benefits to the community in the form of more accurate and insightful diagnostic and preventative healthcare. Recent emerging technologies have provided practitioners with the ability to obtain higher resolution images, and perform faster scans, resulting in greater patient throughput and improved patient comfort.…”

“…Attempts have been made to address the concerns of weight, size and magnetic field nonlinearity [2][3][4] in these magnet systems, with the hope of manufacturing less costly systems.…”

Improvement of MRI magnet design through sensitivity analysis

“…In the analysis of MRI magnets a spherical harmonics expansion of the field can be used: (1) where are the coordinate of the field point and are the Legendre functions of the first kind.…”

“…This design has been obtained by means of an optimized design method [1]. In the nominal configuration the device produces a central field of 3 T with a field homogeneity of 5 ppm over a 10 cm Diameter Spherical Volume (DSV).…”

“…Suitable optimization techniques can be effectively used to choose the magnet geometrical parameters (e.g., dimensions and position of each coil), while satisfying mechanical and physical constraints (e.g., dimensions of the wires and packaging factors or superconductor critical currents) [1]. However, due to the manufacturing and assembling tolerances, the geometry of the actual magnet will differ from the nominal one, affecting the device performances, which usually are very demanding in terms of field homogeneity and strength.…”