The Magnetic Resonance Imaging technique myocardial tagging allows the tracking and measurement of local parameters of heart wall motion. Tagging provides detailed information about regional cardiac function never before available with non-invasive techniques, The growth of this technique has been limited in part by the availability of post-processing tools, We introduce the TAGged cine AnalySIS Tools package (TAGASIST) for the processing of images from this technique. TAGASIST includes a graphical user interface for image segmentation, kinematic analysis, plotting of regional averages as well as multiple subjects (or patient populations) simultaneously, statistical analysis, and a database of all studies processed. (C) 1997 Elsevier Science Ltd.