Bird’s nest sign (lungs)
Citation, DOI, disclosures and article data
At the time the article was created Pradosh Kumar Sarangi had no recorded disclosures.View Pradosh Kumar Sarangi's current disclosures
The bird’s nest sign refers to the appearance created by a reverse halo sign with associated irregular and intersecting areas of stranding or irregular lines within the area of ground-glass opacity 1.
The reverse halo and bird’s nest signs are not specific for invasive fungal disease and may also be seen in other conditions, including 1:
- cryptogenic organizing pneumonia
- bacterial pneumonia
- tuberculosis, sarcoidosis
- Wegener granulomatosis
- pulmonary infarction
Mucormycosis vs aspergillosis
It is important to distinguish mucormycosis from aspergillosis because the treatments can differ (voriconazole is not effective against mucormycosis), and because appropriate early treatment of mucormycosis may improve the outcome.
Imaging features that favor mucormycosis over aspergillus infection in a neutropenic patient are 1-4:
- bird’s nest sign
- >10 pulmonary nodules
- pleural effusion
- concomitant sinusitis and development of infection despite voriconazole prophylaxis
It is to be noted that there has been a rise of mucormycosis in the second wave of the COVID-19 pandemic in India attributed to uncontrolled diabetes and overzealous use of steroids.
- 1. Christopher M. Walker, Gerald F. Abbott, Reginald E. Greene, Jo-Anne O. Shepard, Dharshan Vummidi, Subba R. Digumarthy. Imaging Pulmonary Infection: Classic Signs and Patterns. (2014) American Journal of Roentgenology. doi:10.2214/AJR.13.11463
- 2. Jonathan H. Chung, J. David Godwin, Jason W. Chien, Sudhakar J. Pipavath. Case 160: Pulmonary Mucormycosis1. (2010) Radiology. doi:10.1148/radiol.10081907
- 3. Chamilos, Georgios, Marom, Edith M., Lewis, Russell E., Lionakis, Michail S., Kontoyiannis, Dimitrios P.. Predictors of Pulmonary Zygomycosis versus Invasive Pulmonary Aspergillosis in Patients with Cancer. (2005) Clinical Infectious Diseases. 41 (1): 60. doi:10.1086/430710
- 4. Legouge, C., Caillot, D., Chrétien, M.-L., Lafon, I., Ferrant, E., Audia, S., Pagès, P.-B., Roques, M., Estivalet, L., Martin, L., Maitre, T., Bastie, J.-N., Dalle, F.. The Reversed Halo Sign: Pathognomonic Pattern of Pulmonary Mucormycosis in Leukemic Patients With Neutropenia?. (2014) Clinical Infectious Diseases. 58 (5): 672. doi:10.1093/cid/cit929