morphologic evaluation of ductus diverticulum using multi - detector computed tomography: comparison with traumatic pseudoaneurysm of the aortic isthmus

objectives to evaluate morphologic variations at the aortic isthmus with particular attention to ductus diverticulum, a mimicker of traumatic pseudoaneurysm, and to describe differences using computed tomography (ct) images. patients and methods from december 2013 to december 2014, patients who underwent a chest ct examination after blunt trauma at our emergency department were included. aortic isthmus morphologies were evaluated using multiplanar reconstruction (mpr) and maximum intensity projection (mip) images as follows. type i -concave contour, type ii -convexity without a discrete bulge, or type iii -a discrete focal bulge (defined as ductus diverticulum). conclusion ductus diverticulum, a mimicker of traumatic pseudoaneurysm of the aortic isthmus, is a frequently observed anatomic variant during ct examinations. familiarity with its ct imaging findings could avoid it being confused with traumatic pseudoaneurysm in blunt trauma patients. results after excluding 11 cases of traumatic pseudoaneurysm of the aortic isthmus, a total of 432 trauma patients (mean age = 47.1 ± 19.1 years, number of males = 318) were evaluated for aortic isthmus morphology, and classified as follows; type i (n = 240, 55.6%), type ii (n = 157, 36.3%), and type iii (n = 35, 8.1%). as compared with traumatic pseudoaneurysm (n = 11), ductus diverticulum had a smaller vertical diameter (5.5 ± 1.3 mm vs. 11.2 ± 2.7 mm, p < 0.001), a broader base (14.9 ± 4.1 mm vs. 8.8 ± 4.5 mm, p < 0.001), a smoother margin (97.1% vs. 27.3%, p < 0.001), and formed obtuse angle with the aortic wall. furthermore, ductus diverticulum was not associated with the presence of a dissection flap or hemomediastinum.