There is no relevant literature that compares the diagnostic accuracy of CT chest with IV contrast (delayed-phase enhancement) versus CTA chest (arterial-phase contrast). Suspected Acute Aortic Syndrome Dual-energy multidetector CT enables generation of CT chest images without and with IV contrast enhancement by producing virtual unenhanced imaging studies. However, the use of these virtual unenhanced images in place of true unenhanced images remains controversial [18-20]. CTA Coronary Arteries There is no relevant literature supporting the use of CTA of the coronary arteries for the diagnosis of AAS. CTA of coronary arteries may be used in patients with known AD for which coronary arterial disease classification is needed prior to open surgical repair for an AD involving the ascending aorta. This document includes the triple-rule-out (TRO) protocol under the topic of CTA of coronary arteries as the TRO includes simultaneous assessment of the pulmonary arteries, aorta, and coronary arteries. CTA Chest With IV Contrast CTA can demonstrate the presence of aortic intimal flaps, branch vessel involvement, and entry and reentry sites, as well as identification of penetrating ulcers. The addition of a noncontrast acquisition as part of the CTA examination can be used to confirm the presence of an IMH. CTA chest can also allow for simultaneous assessment of adjacent mediastinal, pericardial, and pleural spaces. CTA chest was the most common initial diagnostic test performed in patients enrolled in the International Registry of Acute Aortic Dissection, and is being used with increasing frequency [21]. CTA was used to diagnose AD with 82% sensitivity and 100% specificity [22]. Numerous prior studies evaluating the accuracy of CT use in diagnosing AD have demonstrated sensitivities of 90% to 100% but lower specificities ranging from 87% to 100% [23-26]. However, these studies evaluated conventional CT, which has largely been supplanted by faster multidetector CT.
Suspected Acute Aortic Syndrome. There is no relevant literature that compares the diagnostic accuracy of CT chest with IV contrast (delayed-phase enhancement) versus CTA chest (arterial-phase contrast). Suspected Acute Aortic Syndrome Dual-energy multidetector CT enables generation of CT chest images without and with IV contrast enhancement by producing virtual unenhanced imaging studies. However, the use of these virtual unenhanced images in place of true unenhanced images remains controversial [18-20]. CTA Coronary Arteries There is no relevant literature supporting the use of CTA of the coronary arteries for the diagnosis of AAS. CTA of coronary arteries may be used in patients with known AD for which coronary arterial disease classification is needed prior to open surgical repair for an AD involving the ascending aorta. This document includes the triple-rule-out (TRO) protocol under the topic of CTA of coronary arteries as the TRO includes simultaneous assessment of the pulmonary arteries, aorta, and coronary arteries. CTA Chest With IV Contrast CTA can demonstrate the presence of aortic intimal flaps, branch vessel involvement, and entry and reentry sites, as well as identification of penetrating ulcers. The addition of a noncontrast acquisition as part of the CTA examination can be used to confirm the presence of an IMH. CTA chest can also allow for simultaneous assessment of adjacent mediastinal, pericardial, and pleural spaces. CTA chest was the most common initial diagnostic test performed in patients enrolled in the International Registry of Acute Aortic Dissection, and is being used with increasing frequency [21]. CTA was used to diagnose AD with 82% sensitivity and 100% specificity [22]. Numerous prior studies evaluating the accuracy of CT use in diagnosing AD have demonstrated sensitivities of 90% to 100% but lower specificities ranging from 87% to 100% [23-26]. However, these studies evaluated conventional CT, which has largely been supplanted by faster multidetector CT.