Abstract: Methods and compositions are provided for monitoring and optimizing electrolysis, for example, tissue electrolysis. Aspects of the methods include monitoring electrolysis of a tissue in a subject using an imaging technique or a measurement technique, e.g., a bulk spectroscopic measurement technique. Imaging techniques of interest include electrical impedance-based tomography and magnetic electrical impedance tomography. Electrical impedance-based imaging methods include imaging the electrical impedance of a tissue of the subject undergoing electrolysis, and monitoring the electrolysis based on one or more electrical impedance images of the tissue. Another modality to monitor electrolysis is by magnetic resonance imaging (MRI)-based methods which include imaging pH changes in a tissue of the subject undergoing electrolysis by magnetic resonance imaging, and monitoring the electrolysis based on one or more magnetic resonance images of the pH changes in the tissue.