Experimental MRI Evidence of the Lift-Off Effect in the Case of a Small High Temperature Superconducting Coil.

Jean-Christophe Ginefri¹, Marie Poirier-Quinot¹, Luc Darrasse¹

The optimization of the SNR achievable with a small High Temperature Superconducting (HTS) surface coil is investigated as a function of the sample size and position using theoretical analysis, inductive measurements, and MRI experiments at 1.5 T. This study was conducted with a 6mm HTS coil operating at 77 K and small conductive saline phantoms. SNR measured on phantom images are in good agreement with theoretical data and inductive measurements and demonstrate the existence of an optimal distance between the sample and the HTS coil for which the SNR is maximum and that depends on the loading configuration.