Coronary angiography to assess the presence and degree of arterial stenosis is an examination now routinely performed on CT scanners. Although developments in CT technology over recent years have made great strides in improving the diagnostic accuracy of this technique, patients with certain characteristics can still be "difficult to image". The various groups will benefit from different technological enhancements depending on the type of challenge they present. Good temporal and spatial resolution, wide longitudinal (z-axis) detector coverage and high X-ray output are the key requirements of a successful CT coronary angiography (CTCA) scan. The requirement for optimal patient dose is a given. The different scanner models recommended for CTCA all excel in different aspects. The specification data presented here for these scanners and the explanation of the impact of the different features should help in making a more informed decision when selecting a scanner for CTCA.
INTRODUCTIONClinical interest in the application of CT for the imaging of coronary vessels dates back to 1998 with the introduction of "four-slice" CT scanners. These early multislice models posed limitations to performing coronary angiography; therefore, their use in cardiac applications was confined to coronary calcium scoring, a technique established on electron beam CT scanners and which has less demanding image quality requirements.