Pulmonary nodules and the CT halo sign

Steven L. Primack, Thomas E. Hartman, Kyung Soo Lee, Nestor L. Müller

Research output: Contribution to journalArticlepeer-review

204 Scopus citations


PURPOSE: To determine whether the 'halo sign' at computed tomography (CT) could be used to differentiate hemorrhagic from nonhemorrhagic pulmonary nodules. MATERIALS AND METHODS: CT scans of 12 patients with hemorrhagic pulmonary nodules and of a control group of 10 patients with nonhemorrhagic pulmonary nodules were randomized and reviewed by two chest radiologists. Nodules were considered hemorrhagic if a surrounding halo of ground-glass attenuation was present. RESULTS: Nodules were correctly identified as either hemorrhagic or nonhemorrhagic by both observers in 19 of the 22 cases (86%). Eight of the 12 patients with hemorrhagic nodules had an infectious process including invasive aspergillosis, candidiasis, cytomegalovirus, herpes simplex virus, or coccidioidomycosis. Four of 12 patients with hemorrhagic nodules had a noninfectious cause including Wegener granulomatosis, metastatic angiosarcoma, and Kaposi sarcoma. CONCLUSION: Most hemorrhagic pulmonary nodules have a characteristic CT appearance consisting of a central area of soft-tissue attenuation with a surrounding halo of ground-glass attenuation that allows distinction from nonhemorrhagic nodules.

Original languageEnglish (US)
Pages (from-to)513-515
Number of pages3
Issue number2
StatePublished - Feb 1994


  • Aspergillosis
  • Candidiasis
  • Coccidioidomycosis
  • Cytomegalovirus
  • Lung neoplasms, secondary
  • Lung, infection
  • Lung, nodule
  • Wegener granulomatosis

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


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