[CT features and anatomic-pathologic basis of the 16-slice spiral CT for aortic dissection].

Objective: To determine the CT features and anatomic-pathologic basis of the 16-slice Spiral CT (SCT) for aortic dissection (AD).
Methods: Forty-two cases with typical aortic dissection (AD) and 12 cases with intramural hematoma (IMH) underwent 16-slice SCT, performed with unenhanced, contrast-enhanced scanning and three-dimensional reconstruction. More attention was put on the true and false lumen, intimal flap, the entry tear and the involvement of branches of AD.
Results: (1) True and false lumen and intimal flap of AD could be shown in all of 42 cases (100%), the entry tears were revealed in 41 cases (97.6%), and the true and false lumen and intimal flap extended spirally in 41 cases (97.6%). (2) For intramural hematoma (IMH), unenhanced CT depicted crescent-shaped areas with high attenuation extending along the walls of the aorta in 10 cases (83.3%), and low attenuation in 2 cases (16.7%), while contrast-enhanced CT showed no enhancement of attenuation in the crescent-shaped areas in all 12 cases. Nine cases (75%) of IMH were associated with penetrating aortic ulcer.
Conclusions: The axial and three-dimensional images of 16-slice SCT can fast and exactly reveal the pathological and anatomical features of AD, and provide detailed imaging information for clinical therapy. It's very important for the selection of treatment methods.