Accurate and timely assessment of suspected acute aortic syndrome (AAS) is crucial in this life-threatening condition. Imaging with computed tomography (CT) plays a central role in the diagnosis to allow expedited management. Diagnosis can be made using locally available expertise with optimised scanning parameters making full use of recent advances in CT technology. Each imaging centre must optimise their protocols to allow accurate diagnosis, optimise radiation dose, and in particular to reduce the risk of false positive diagnosis that may simulate disease. This document outlines principles for the acquisition of motion-free imaging of the aorta in this context.