PT - JOURNAL ARTICLE AU - Venkata N Maturu AU - Ritesh Agarwal TI - Reversed Halo Sign: A Systematic Review AID - 10.4187/respcare.03020 DP - 2014 Sep 01 TA - Respiratory Care PG - 1440--1449 VI - 59 IP - 9 4099 - http://rc.rcjournal.com/content/59/9/1440.short 4100 - http://rc.rcjournal.com/content/59/9/1440.full AB - A reversed halo sign (RHS) is defined as the presence of a focal ring-shaped area of ground-glass opacity within a peripheral rim of consolidation. Although originally described in patients with cryptogenic organizing pneumonia, it has been described with several other noninfectious and infectious diseases, including fungal infections. Thus, it is imperative that a proper diagnosis be established before initiating treatment. In this article, we systematically review the literature (PubMed and Embase) for the associations of the RHS. We have also proposed a diagnostic algorithm for an approach to a patient with an RHS.