Feasibility of real-time 1.5-T MR-guided percutaneous irreversible electroporation in a porcine model

Abstract This exploratory study assessed the procedural feasibility of in‑bore, real‑time magnetic resonance (MR)‑guided percutaneous irreversible electroporation (IRE) using a clinical 1.5-T system in a porcine model. Three healthy anesthetized juvenile swine underwent IRE in normal renal tissue using a prototype pulse generator and MR-conditional coaxial cannula as electrodes. One swine was ablated twice in the same kidney, resulting in statistically non-independent data. The procedure was guided by a balanced steady-state free precession sequence with orthogonal slices and intermittent position verifications using a radial three-dimensional gradient-echo sequence. Preprocedure radiofrequency noise and signal-to-noise ratio measurements showed slightly increased noise levels in generator standby mode without apparent imaging artifacts. Median procedure time was 48 min with an interquartile range of 17 min. Four hours post-procedure, the treatment zone appeared T1-hypointense in delayed contrast-enhanced imaging. For one treatment zone, hematoxylin and eosin staining (H&E), fluorescent terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining (TUNEL), and coregistration to MR imaging were performed. H&E showed minor hemorrhaging at the site of electrode insertion. TUNEL demonstrated a strong TUNEL-positive signal correlating with the T1-hypointense signal in delayed contrast-enhanced imaging, with a Dice-Sørensen coefficient of 67%. These findings demonstrate the procedural feasibility of MR-guided percutaneous IRE in clinical 1.5-T MR systems. Key Points Question Can MR-guided percutaneous irreversible electroporation be performed in a porcine model despite the lack of MR-compliant devices? Findings In four irreversible electroporation procedures in three juvenile pigs, electrodes were successfully placed in the kidney using real-time guidance in a clinical 1.5-T scanner. Relevance statement Real-time MR-guided percutaneous irreversible electroporation is procedurally feasible in a clinical 1.5-T MRI environment, while preserving image quality and enabling arbitrary slice positioning. Further research is required to confirm the reproducibility and enable the translation to oncological applications.