The 'DIMPLE SIGN' of Intra-Aortic Cord.

Background: With increasing use of imaging to diagnose human pathology, newer aortic anomalies are being identified. An intra-aortic cord is one such abnormality, which requires differentiating from an intimal flap of dissection, to avoid major surgery or prolonged surveillance. The aim of this study was to bring forth a unique feature of the intra-aortic cord on imaging, using volume rendering reformatting and identify similar findings in published literature and hence establish the role of the 'Dimple' sign.

Methods: Review of both our institutional imaging (2 cases) as well as the published literature (6 cases), to identify presence of a diagnostic sign that is seen on volume rendered imaging of aorta.

Results: The 'Dimple sign' is unique to the intra-aortic cord and is noted on the images of 4 out of 6 prior publications. Two publications did not use volume rendering. Including our cases, the Dimple' sign is seen in 6 out of 8 cases. The Dimple sign arises due to tethering of the cord to the aortic wall leading to umbilication of the aortic wall inwards.

Conclusions: The Dimple sign can be very easily noted on volume and/or cinematic rendering and is a useful sign to diagnose an intra-aortic cord and help differentiate it from an intimal flap.