Magnetic Resonance Imaging Depiction of Non Thermal Irreversible Electroporation Treated Liver

Abstract

Non-thermal irreversible electroporation (NTIRE) is a minimally invasive tissue ablation modality in which pulsed electric fields are delivered across the cell to produce nanoscale defects in the cell membrane and cell death. Medical imaging is of great importance for any ablation technology for obtaining maximum treatment efficacy with minimum damage to surrounding normal tissue. Previous studies of medical imaging of NTIRE have focused primarily on the correlation between the extent of tissue ablation and the image. The purpose of the presented study was to seek a physiological interpretation of MRI images of NTIRE, rather than a correlation between the image and the extent of tissue death. To develop a fundamental understanding of the physiological significance of the MRI images, we compared MR imaging sequences of T1W, T2W, PD, T2 SPAIR, and STIR acquired after NTIRE treatment in a rodent liver model. The parameters that were studied include the presence or absence of a contrast agent and in vivo and ex-vivo NTIRE treatments in the same liver. The most striking observations is that the same MRI sequences that produce an image after NTIRE in vivo fail to produce an MRI image when NTIRE is delivered ex-vivo, within minutes after the excision of the organ. This tentatively suggests that the physiological interpretation of the MRI images is related to blood flow and blood flow phenomena.