Heartbeat-related displacement of the thoracic aorta in patients with chronic aortic dissection type B: quantification by dynamic CTA.
OBJECTIVE
The purpose of this study was to characterize the heartbeat-related displacement of the thoracic aorta in patients with chronic aortic dissection type B (CADB).


METHODS
Electrocardiogram-gated computed tomography angiography was performed during inspiratory breath-hold in 11 patients with CADB: Collimation 16 mm x 1 mm, pitch 0.2, slice thickness 1mm, reconstruction increment 0.8 mm. Multiplanar reformations were taken for 20 equidistant time instances through both ascending (AAo) and descending aorta (true lumen, DAoT; false lumen, DAoF) and the vertex of the aortic arch (VA). In-plane vessel displacement was determined by region of interest analysis.


RESULTS
Mean displacement was 5.2+/-1.7 mm (AAo), 1.6+/-1.0 mm (VA), 0.9+/-0.4 mm (DAoT), and 1.1+/-0.4mm (DAoF). This indicated a significant reduction of displacement from AAo to VA and DAoT (p<0.05). The direction of displacement was anterior for AAo and cranial for VA.


CONCLUSIONS
In CADB, the thoracic aorta undergoes a heartbeat-related displacement that exhibits an unbalanced distribution of magnitude and direction along the thoracic vessel course. Since consecutive traction forces on the aortic wall have to be assumed, these observations may have implications on pathogenesis of and treatment strategies for CADB.
Weber
Tim F
TF
University of Heidelberg, Department of Diagnostic and Interventional Radiology, 69120 Heidelberg, Germany. tim.weber@med.uni-heidelberg.de
Ganten
Maria-Katharina
MK
Böckler
Dittmar
D
Geisbüsch
Philipp
P
Kauczor
Hans-Ulrich
HU
von Tengg-Kobligk
Hendrik
H
D000784:Aortic Dissection / Q000000981:diagnostic imaging*; D000792:Angiography / Q000379:methods*; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011860:Radiography, Abdominal; D013902:Radiography, Thoracic / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*