An interdisciplinary study from the University of Virginia was reported in a recent issue of the Journal of the American Medical Association (JAMA) [1]. The results of that study are pertinent to radiologists who interpret CT scans for patients with chronic sinus disease. The study examined the relationship among eosinophilia, asthma, allergy, and sinusitis and assessed the findings obtained for the paranasal sinuses by high-resolution CT. Soft-tissue disease seen within the paranasal sinuses on CT scans is often described as mucosal thickening or mucoperiosteal thickening, with little attention to its exact nature. The JAMA article showed that for patients properly prepared for sinus CT, the thickened mucosa depicted within the sinonasal cavity is a significant site of functional, immunologically active tissue. The purpose of this article is to bring the findings of the JAMA report to the attention of radiologists and to emphasize the imaging technique, findings, and clinical relevance of the results.