Myrna Cobos Barco Godoy MD, Presenter: Nothing to Disclose

Chitra Viswanathan MD, Abstract Co-Author: Nothing to Disclose

Mylene Thi Mytien Truong MD, Abstract Co-Author: Nothing to Disclose

Edson Marchiori MD, PhD, Abstract Co-Author: Nothing to Disclose

Marcelo Kuperman Benveniste MD, Abstract Co-Author: Nothing to Disclose

Edith Michelle Marom MD, Abstract Co-Author: Nothing to Disclose

Santiago E. Rossi MD, Abstract Co-Author: Nothing to Disclose

The purpose of this exhibit is: To describe and illustrate the spectrum of neoplastic and non-neoplastic conditions that may show the reversed halo sign (RHS) with emphasis on new differential diagnosis. To offer clinical and radiologic clues that are helpful in narrowing the differential diagnosis.

The RHS is a focal ground glass opacity surrounded by a ring of consolidation on CT. Initially described in cryptogenic organizing pneumonia, the RHS has also been reported in association with a wide range of pulmonary diseases including invasive pulmonary fungal infections, tuberculosis, sarcoidosis, and Wegener granulomatosis. In neoplastic diseases, particularly following radiation therapy and radiofrequency ablation, it should not be misinterpreted as disease progression.

Knowledge of the spectrum of diseases that may manifest as a reverse halo sign, correlation with patient clinical information and use of ancillary CT findings are important in making the diagnosis that can impact patient management.

Godoy, M, Viswanathan, C, Truong, M, Marchiori, E, Benveniste, M, Marom, E, Rossi, S, The Reversed Halo Sign: Update and Differential Diagnosis.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11006092.html