title: Radiologic characteristics of sinonasal fungus ball: an analysis of 119 cases.
abstract: BACKGROUND
  It is important to differentiate sinonasal fungus ball from non-fungal sinusitis and other forms of fungal sinusitis in order to determine the optimal treatment. In particular, a sinonasal fungus ball, a non-invasive fungal sinusitis, can be characterized by radiologic findings before surgery.
  
  
  OBJECTIVE
  To differentiate a sinonasal fungus ball from other types of sinusitis and determine optimal treatment on the basis of radiologic findings before surgery.
  
  
  METHODS
  We studied 119 patients with clinically and pathologically proven sinonasal fungus balls. Their condition was evaluated radiologically with contrast-enhanced CT (99 patients), non-contrast CT (18 patients) and/or MRI (17 patients) prior to sinonasal surgery.
  
  
  RESULTS
  Calcifications were found in 78 of 116 (67.2%) patients who underwent CT scans for fungus ball. As opposed to non-contrast CT scans, contrast CT scans revealed hyperattenuating fungal ball in 82.8% and enhanced inflamed mucosa in 65.5% of the patients, respectively. On MRI, most sinonasal fungal balls showed iso- or hypointensity on T1-weighted images and marked hypointensity on T2-weighted images. Inflamed mucosal membranes were noted and appeared as hypointense on T1-weighted images (64.7%) and hyperintense on T2-weighted images (88.2%).
  
  
  CONCLUSIONS
  When there are no calcifications visible on the CT scan, a hyperattenuating fungal ball located in the central area of the sinus with mucosal thickening on enhanced CT scans is an important feature of a non-invasive sinonasal fungus ball. On MRI, a sinonasal fungus ball has typical features of a marked hypointense fungus ball with a hyperintense mucosal membrane in T2-weighted images. A contrast-enhanced CT scan or MRI provides sufficient information for the preoperative differentiation of a sinonasal fungus ball from other forms of sinusitis.
authors.affiliation: Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Seo
authors.forename: Jinna
authors.initials: J
authors.lastname: Kim
authors.forename: Kyubo
authors.initials: K
authors.lastname: Kim
authors.forename: Jeung-Gweon
authors.initials: JG
authors.lastname: Lee
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Kim
authors.forename: Joo-Heon
authors.initials: JH
authors.lastname: Yoon
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000175:diagnosis*; D010254:Paranasal Sinus Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000382:microbiology*; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media