This study examines conductivity mapping using MR Electrical Properties Tomography (MREPT) at ultra-high field (21.1 T). The accuracy of reconstructing conductivity using the complex B1+ field (Full-form) versus only the B1+ phase (Phase-based) is evaluated. Phantoms containing different NaCl concentrations were tested to compare these reconstructions with actual conductivities measured by dielectric probe at 900 MHz. Also, these methods were evaluated for experiments acquired with volume and surface coil configurations operated in either linear or quadrature transceiver. Conductivity maps of Full-form versus Phase-based MREPT from in vivo MCAO rats were acquired, with both providing similar variations across the ischemic brain.