Type A Aortic Dissection and Non-Contrast Computed Tomography

Abstract

Non-contrast enhanced chest computed tomography (CT) carries a low sensitivity for acute aortic dissection; CT Angiography remains the gold standard. We highlight the potential utility of non-contrast CT for detection of aortic dissection in a case of a young, immunocompromised man presenting with acute abdominal pain and renal injury. Given elevated creatinine, an initial non-contrast chest CT demonstrated subtle findings suggestive of aortic dissection (aneurysmal dilation of the proximal ascending aorta as well as displaced calcified intimal flap/intraluminal high linear density in the thoracic descending and distal abdominal aorta). Subsequent CT angiography confirmed the presence of an extensive type A aortic dissection. He underwent emergent exploratory laparotomy and hemiarch repair. Displaced calcified intimal flaps, intraluminal high-densities, intramural hematoma, and aneurysmal aortic dilation are common non-contrast computed tomography imaging findings that suggest aortic dissection.

Keywords: Acquired immunodeficiency syndrome; Aortic Dissection; Hypertensive emergency; Non-contrast computed tomography.

Fig. 1

Non-contrast Computed Tomography demonstrating subtle findings suggestive of Aortic Dissection. Evidence of aneurysmal dilation of the proximal ascending aorta (A), ongoing aneurysmal dilation with a noted displaced calcified intimal flap/intraluminal high linear density in of the thoracic descending aorta (B) and distal abdominal aorta (C).

Fig. 2

Computed Tomography Angiography demonstrating extensive Type A aortic dissection extending from the sinus of Valsalva to the common iliac arteries with involvement of the ascending (A) and arch of the aorta (B), subclavian artery (C), right common carotid and right subclavian arteries (D), celiac artery (E), bilateral renal arteries (F), superior mesenteric artery with complete thrombosis (G), and common iliac arteries (H). Comparison of the Computed Tomography Angiography and non-contrast studies demonstrates evidence of dissection at the same level, highlighting pertinent non-contrast imaging findings corresponding to the respective contrasted studies at the level of the descending thoracic aorta (I, J) and distal abdominal aorta (K, L).