Wave-Number Imaging at 7T: Increasing Accuracy of EPT at High Field Strengths

Astrid L.H.M.W. van Lier¹, Ulrich Katscher², Alexander Raaijmakers¹, Cornelis A.T. van den Berg¹

Recently, it was shown that dielectric properties can be mapped using MRI. Electrical properties mapping relies on measurements of the B₁⁺ amplitude and phase. This phase, however, cannot be measured directly; therefore, the assumption that the transceive phase is twice the B₁⁺ phase is used in a transceiver setup. This assumption is acceptable at low field strengths, however, leads to significant reconstruction errors at 7T. Here we show, that the wave-number (|k|) is less susceptible to these errors, and can be mapped more reliably than the permittivity and conductivity at 7T.