Cinematic display of respiratory organ motion with impedance techniques

A technique is described for the recording of individual images during discrete phases of the respiratory cycle, i.e., isovolume images. The method is based on the observation that transthoracic impedance is related approximately linearly to lung volume. This impedance signal can be converted to an FM signal to stimulate a Z pulse, then added in parallel to the Z pulse from the gamma camera. Simulated X and Y position signals locate simulated Z at the periphery of the computer field of view. Summation of the images with coinciding simulated Z counts produces isovolume images, one for each phase of respiration. These images then can be displayed in cinematic mode or as motion-corrected images. This new technique offers a potential for improved image resolution, temporal separation of organs that exhibit different motion patterns, and estimation of regional pulmonary function.