Hilum overlay sign
Citation, DOI, disclosures and article data
Citation:
Gaillard F, Silverstone L, Spires R, et al. Hilum overlay sign. Reference article, Radiopaedia.org (Accessed on 08 Feb 2025) https://doi.org/10.53347/rID-15494
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rID:
15494
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At the time the article was created Frank Gaillard had no recorded disclosures.
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At the time the article was last revised Liz Silverstone had no financial relationships to ineligible companies to disclose.
View Liz Silverstone's current disclosures
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The hilum overlay sign can help determine the position of an opacity on a frontal radiograph. Hilar vessels adjacent to aerated lung are sharply marginated. If that lung is displaced or opacified, the silhouette is obliterated, (silhouette sign). A hilar mass will obscure the vascular margins 2 whereas an anterior or posterior mass will overlay the vessels but the vessel margins will still be clear (hilum overlay sign).
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Etiology
anterior mediastinal masses - may also obscure the right heart border
hilar adenopathy
If the pulmonary arteries are visible more than a centimeter within the lateral edge of the mediastinal silhouette, then the lesion is not cardiac in origin.
History and etymology
Benjamin Felson (1913-1988) was the American radiologist who first described this sign 3. Moreover, in more than 98% of the chest radiographs he reviewed, the visible proximal segment of the pulmonary artery was lateral to or just within the cardiac silhouette. Even when the heart is enlarged or there is pericardial effusion, this relationship remains true 4.
See also
References
- 1. Coche EE, Ghaye B, Mey JD. Comparative Interpretation of CT and Standard Radiography of the Chest. Springer Verlag. (2010) ISBN:3540799419. Read it at Google Books - Find it at Amazon
- 2. William E. Brant. Fundamentals of Diagnostic Radiology - 4 Volume Set. ISBN: 9781608319121
- 3. George PP, Irodi A, Nidugala Keshava S et-al. 'Felson Signs' revisited. J Med Imaging Radiat Oncol. 2014;58 (1): 64-74. doi:10.1111/1754-9485.12031 - Pubmed citation
- 4. Parker MS, Chasen MH, Paul N. Radiologic signs in thoracic imaging: case-based review and self-assessment module. (2009) AJR. American journal of roentgenology. 192 (3 Suppl): S34-48. doi:10.2214/AJR.07.7081 - Pubmed
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Articles:
Cases:
- Anterior mediastinal mass with hilum overlay sign
- Dense hilum sign
- Round pneumonia
- Thymoma
- Hilum overlay sign
- Non-invasive thymoma
- Cerebellar metastasis
- Right hilar mass
- Primary mediastinal B-cell lymphoma
- Thoracic aortic aneurysm
- Hilum overlay sign
- Mediastinal teratoma
- Morgagni hernia
- Pneumonia at superior segment of right lower lobe (hidden area)
- Hilum overlay sign
- Pneumonia with hilum overlay sign
- Mediastinal high-grade pleomorphic sarcoma
- Squamous cell carcinoma of the lung with hilum overlay sign
- Lung cancer - hilum overlay sign
- Hilum overlay sign - mediastinal lymphoma
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