An FMRI Phantom Based on the Alignment of Molecular Dipoles with an Electric Field

Yujie Qiu¹, Edmund Kwok², Joseph P. Hornak¹

A new concept for an fMRI phantom is presented where the T₂ of a non-viscous, high dielectric constant liquid is changed by the application of an electric field. The electric field aligns the dipoles in the liquid, thus changing the molecular motions and T₂. The T₂ value of propylene carbonate was changed from 45 to 36 ms by the application of a 116 V/cm electric field. This T₂ change will produce a 15% change in the signal, comparable to the 5-20% seen for the BOLD response. This concept may allow changing the T₂ at rates comparable to the BOLD response.