Computed tomographic (CT) angiography is an important imaging modality in the evaluation of the vascular system throughout the body. Single-channel spiral CT permits diagnostic imaging of various vascular diseases (1,2). Because of the three-dimensional visualization possibilities, CT angiography seems to be superior even to conventional angiography in certain vascular territories (3,4). Moreover, CT angiography compared with conventional angiography has the advantage of being a noninvasive technique, consuming fewer resources, and being more cost-efficient (5). With the recent introduction of multi-detector row spiral CT with subsecond rotation time, the temporal and spatial resolution of CT angiography has improved (2,6-8).
Despite these improvements, certain vascular areas are still vulnerable to motion artifacts. The thoracic aorta is known to cause many diagnostic difficulties and pitfalls in CT imaging, especially in patients suspected of having aortic dissection (9-12). Batra et al (13) categorized several possible pitfalls that occur during single-channel spiral CT of the thoracic aorta. Technical factors, streak artifacts, periaortic structures, aortic wall motion, aortic variations, and atherosclerotic plaques may simulate aortic dissection.
The recent introduction of prospective and retrospective electrocardiographically (ECG)-assisted imaging in combination with multi-detector row CT has created interest in cardiac and, especially, coronary artery imaging (14). Yet, to our knowledge, no study has been performed to determine the influence of ECG-assisted imaging of the thoracic aorta and its adjacent regions with regard to motion artifact reduction. The purpose of this study was to evaluate prospective and retrospective ECG-assisted multi-detector row CT of the thoracic aorta, in comparison with non-ECG-assisted multi-detector row spiral CT, with regard to reduction of motion-related artifacts.