Current generation Helical Computed Tomography, when coupled with cardiac gating can be used to measure coronary vascular calcium. In this article we review the development of retrospectively gated helical computed tomography on a single slice HCT system and its relation to electron beam CT. The impact of heart rate on selection of helical pitch for the creation of a diastolic image set is detailed, as well as, scanning and post-processing techniques are discussed. The development and initial experience of cardiac gating with multidetector CT systems is presented.