title: Morphologic Evaluation of Ductus Diverticulum Using Multi - Detector Computed Tomography: Comparison with Traumatic Pseudoaneurysm of the Aortic Isthmus.
abstract: OBJECTIVE
  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.
  
  
  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).
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Jun
authors.initials: J
authors.lastname: Hyung Ann
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Eun
authors.initials: E
authors.lastname: Young Kim
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Yu
authors.initials: Y
authors.lastname: Mi Jeong
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Jeong
authors.initials: J
authors.lastname: Ho Kim
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Hyung
authors.initials: H
authors.lastname: Sik Kim
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Hye-Young
authors.initials: HY
authors.lastname: Choi
keywords: Aorta, Thoracic; Ductus Diverticulum; Tomography, X-ray Computed; Trauma