A focal corrugated bulging of the right ventricular wall, seen by axial MRI in asymptomatic patients with early arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The accordion sign contrasts to left-ventricular involvement, a relatively late MR finding in these patients.
A term referring to the periodic “crumpling” of 2 distinct alternating imaging densities, which has been described in the heart in PKP2 mutations, the colon in pseudomembranous colitis or splenic rupture, the jejunum in systemic sclerosis and in crumpled and shortened long bones, especially the femur, in children with type-II osteogenesis imperfecta.
Compression and medial displacement of a calcified splenic artery, which, when seen on the plain abdominal film of trauma victims, has been fancifully likened to an accordion and is suggestive of splenic rupture or haematoma formation.
(1) A finding in upper-GI contrast studies of advanced progressive systemic sclerosis, where the jejunum is dilated and foreshortened with mural fibrosis and the valvulae conniventes are of normal thickness, imparting a corrugated appearance in the contrast column.
(2) A finding by CT in pseudomembranous colitis in which contrast is trapped between colonic folds—valvulae conniventes—thickened by submucosal oedema, especially in Clostridium difficile colitis.
Other radiologic findings in the GI tract in progressive systemic sclerosis include pneumatosis intestinalis, pseudo-obstruction, intussusception, sacculations and volvulus of the small intestine.
Crumpling and shortening of long bones, especially the femur, seen in type-II osteogenesis imperfecta, a disease accompanied by low birth weight, beading of the ribs, early death due to respiratory insufficiency resulting from a defective thoracic cage, softened skull, fragile skin with defective type-I collagen; heredity is variable; affects 1:60,000 live births, half are stillborn.