title: Leiomyoma of the sinonasal cavity: CT and MRI findings.
abstract: OBJECTIVE
  To determine the computed tomography (CT) and magnetic resonance imaging (MRI) features of leiomyoma of the sinonasal cavity.
  
  
  METHODS
  Six patients with histology-proven leiomyomas in the sinonasal cavity were retrospectively reviewed. All six patients underwent CT and three patients also underwent MRI. The following imaging features were reviewed: size, margin, CT attenuation, MRI signal intensity, and lesion extent. In addition, the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) were analysed in two patients.
  
  
  RESULTS
  All leiomyomas had well-defined margins. The mean size was 36 mm (range 20-51 mm). On unenhanced CT, the lesions appeared isodense to cerebral grey matter in four (67%) and slightly hypodense in two (33%) patients. Leiomyomas appeared isointense On T1-weighted imaging (WI) and slightly hyperintense on T2WI in three patients. The lesions showed moderate contrast enhancement. Two patients underwent DCE MRI, and the TIC showed a rapidly enhancing and slow washout pattern. The mean apparent diffusion coefficient (ADC) value were 1.66x10(-3) mm(2)/s and 1.78x10(-3) mm(2)/s for the two lesions, respectively.
  
  
  CONCLUSIONS
  Well-defined, homogeneous, expansile masses without bony erosion are typical features of leiomyoma. Althrough rare, this entity should be included in the differential diagnosis of benign tumours in this region.
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China. cjr.yangbentao@vip.163.com
authors.forename: B T
authors.initials: BT
authors.lastname: Yang
authors.forename: Z C
authors.initials: ZC
authors.lastname: Wang
authors.forename: J F
authors.initials: JF
authors.lastname: Xian
authors.forename: D P
authors.initials: DP
authors.lastname: Hao
authors.forename: Q H
authors.initials: QH
authors.lastname: Chen
mesh_terms: D000328:Adult; D003287:Contrast Media; D005005:Ethmoid Sinus / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007889:Leiomyoma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008444:Maxillary Sinus Neoplasms / Q000175:diagnosis; D008875:Middle Aged; D009296:Nasal Cavity / Q000000981:diagnostic imaging; D009669:Nose Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010255:Paranasal Sinus Neoplasms / Q000175:diagnosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media