title: Obscured aortic arch on the lateral view as a sign of coarctation.
abstract: Forty patients with coarctation of the aorta were compared with 80 normal subjects matched by sex and age. The aortic arch was invisible on the lateral radiograph in 84% of patients preoperatively and 88% postoperatively. Only 6 normal subjects (8%) had a similar finding. The authors conclude that an obscured aortic arch on the lateral view could be a clue to the presence of coarctation. Possible explanations for this phenomenon include (a) dilatation of the brachiocephalic arteries (particularly the left subclavian artery), obscuring the superior margin of the arch; (b) hypoplasia and anteromedial displacement of the distal portion of the arch; and (c) diffuse hypoplasia of the arch combined with focal coarctation.
mesh_terms: D000293:Adolescent; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D001017:Aortic Coarctation / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography