Medical imaging of electroporation

Abstract

Irreversible electroporation (IRE) is emerging as an important option for the minimally invasive focal ablation of tumors in the liver, pancreas, prostate, and kidney. Imaging plays a crucial role in selection of appropriate pulse parameters, electrode placement, monitoring of pulse delivery, and evaluating outcomes of IRE. The ability to clearly distinguish between regions of reversible and irreversible electroporation is crucial for the effective treatment of tumors. As electroporation itself cannot be directly visualized in patients, the imaging of tissue changes that arise following electroporation such as changes in perfusion, vascular permeability, diffusion, and functional or metabolic state of tissue is used to monitor IRE in patients. Several imaging techniques, such as computed tomography (CT), ultrasound (US), magnetic resonance imaging (MRI), and positron emission tomography (PET) are now used for guiding and assessing IRE in vivo. In this chapter, typical imaging features that manifest following IRE are discussed and the physiologic effects that underlie these features as seen with different imaging techniques in malignant and normal tissue in the liver, prostate, and other major organs are described.