Imaging description

A common artifact that can mimic blunt traumatic aortic injury (BTAI) or an aortic dissection is pulsation artifact. This artifact occurs most commonly in the ascending aorta, but it may occur elsewhere in the thoracic aorta, including the aortic isthmus ([1–4]. Pulsation artifacts have been identified in up to 92% of non-ECG-gated CT scans [3]. Blunt traumatic aortic injuries involving the ascending aorta and root are extremely rarely encounted in the emergency department as these patients almost always die before reaching the hospital [4–6]. In the vast majority of cases, pulsation artifact affects the left anterior and right posterior aspects of the aortic circumference [3]. This artifact, which can also simulate aortic dissection, is described in more detail in Case 43. Important differentiating features are extension of the linear hypodensity of pulsation artifact into the mediastinal fat, and similar “pseudoflaps” in the main pulmonary artery and superior vena cava at the same slice level (Figure 39.1). Multiplanar reformations can be very useful. Other helpful differentiating features include the absence of periaortic hematoma (in suspected BTAI) and the presence of similar artifacts on adjacent structures such as tubes and lines (Figure 39.2).