signet ring sign

Beyond
bronchitis: a review of the congenital and acquired abnormalities of the bronchus. Classic imaging signs of bronchiectasis. a Signet ring sign is a CT finding referring to a markedly enlarged bronchus (*) mimicking a ring and its adjacent normal accompanying pulmonary artery representing the signet emblem of the ring (arrow). b Finger-in-glove sign describes the presence of mucous or fluid impaction within a dilated bronchus (dashed arrow) appearing as a radiopaque “finger” in the “glove” of the bronchus
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The clothes
maketh the sign. Axial high resolution CT image of dilated airways in a 19-year-old woman with cystic fibrosis. The airway diameter exceeds that of adjacent pulmonary artery resembling a jewelled or signet ring (inset)
insightsimaging.springeropen.com • Open Access
COVID-19
versus H1N1: challenges in radiological diagnosis—comparative study on 130 patients using chest HRCT. Mixed parenchymal/alveolar and airway abnormalities seen with H1N1: 47-year-old male H1N1 patient. a Axial HRCT chest lung window with “MIP” reconstruction demonstrating tree in bud nodules (blue arrows) and small ground-glass opacities. b Axial HRCT lung window showing mild bronchiectatic changes with “signet ring sign” (red arrows), patchy areas of mild air trapping (yellow arrows), and tiny few right lower sub-pleural tree in bud nodules (green arrow)
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Radiopaedia • CC-by-nc-sa 3.0 • de

The signet ring sign is seen in bronchiectasis when the dilated bronchus and accompanying pulmonary artery branch are seen in cross-section. The bronchus and artery should be the same size, whereas in bronchiectasis, the bronchus is markedly dilated.

The signet ring analogy has also been applied to the scaphoid when it demonstrates a cortical ring as result of foreshortening on a PA projection, suggestive of volar rotation of the scaphoid secondary to scapholunate dissociation. This may also be a normal projectional finding, seen without dissociation as well .

An obscure use of the signet ring appearance has also been described in intravenous urography of renal papillary necrosis, where contrast fills the circumferential fornix of the necrotic papillae .

History and etymology

Signet rings were worn by nobles to enable them to place their seal in wax.

Siehe auch:
Assoziationen und Differentialdiagnosen zu signet ring sign: