We introduce a framework to characterize and visualize the transverse tubular system of cardiac myocytes imaged with confocal microscopy. We imaged rabbit ventricular cells and cell segments with fluorescein linked to dextran. The image datasets were deconvolved with the Richardson-Lucy algorithm using the point spread function extracted from images of fluorescent beads. The transverse tubular system (t-system) was segmented with the methods of digital image processing. We reconstructed single transverse tubules and quantitatively described these in terms of length, cross-sectional area, ellipticity and orientation. These results should yield geometric markers for studies of protein distribution and provide insights into the function of the t-system.