Electrical impedance monitoring of a tissue or an organ for perfusion or viability has been limited by sensitivity and baseline shifts. An apparatus and method are described which improve sensitivity by making the intervening tissue between pairs of electrodes a determinant component of electrical resonance. Such sensitivity further enhances detection of the pulsatile component of blood flow within a tissue. Baseline shift can be monitored and compensated due to resonance shift. The method is adaptable to sufficiency of perfusion monitoring or viability, imaging by 2-dimensional or 3-dimensional electrical impedance tomography, monitoring of tissue ablation by thermal or chemical methods, and thermoplasty of tissues to alter their form and functionality.
