title: 3D-FIESTA MRI at 3 T demonstrating branches of the intraparotid facial nerve, parotid ducts and relation with benign parotid tumours.
abstract: OBJECTIVE
  To investigate the usefulness of three-dimensional (3D) fast imaging employing steady state precession (FIESTA) magnetic resonance imaging (MRI) at 3 T in evaluating the intraparotid components of the facial nerve and parotid ducts, and to compare the MRI images with surgical findings.
  
  
  METHODS
  Thirty-one cases of benign parotid tumours were studied with conventional and 3D FIESTA MRI sequences at 3T using a head coil. The most clinically useful 3D FIESTA images were acquired at parameters of 4.9 ms repetition time (TR); 1.5 effective echo time (TEeff); a flip of 55°, a field of view of 18 to 20 cm, a matrix of 512 × 320, an axial plane, no gaps, and a section thickness of 1 mm. Post-processed multiplanar images were obtained with an Advantage Windows (AW sdc 4.3) workstation. Parotid ducts, facial nerves, and tumours were identified on these images. The relationship of the tumours to the facial nerves and parotid ducts was confirmed at surgery.
  
  
  RESULTS
  The facial nerves appeared as linear structures of low intensity. The main trunk of the facial nerve was identified bilaterally in 93.5% of the 3D-FIESTA sequence images. Parotid ducts appeared as structures of high intensity on multiplanar 3D-FIESTA images (100%). The relationships of the tumours with the cervicofacial and temporofacial divisions of the facial nerve were correctly diagnosed in 26 of 31 cases (83.9%) using 3D-FIESTA sequence images.
  
  
  CONCLUSIONS
  3D-FIESTA MRI at 3 T depicted the main trunk, cervicofacial and temporofacial divisions of the facial nerve, and the main parotid duct. It is useful for preoperative evaluation of parotid gland tumours.
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan 250021, China. lichuanting@yeah.net
authors.forename: Chuanting
authors.initials: C
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhang
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Yang
authors.forename: Lebin
authors.initials: L
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005154:Facial Nerve / Q000033:anatomy & histology / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000033:anatomy & histology / Q000294:innervation* / Q000473:pathology; D010307:Parotid Neoplasms / Q000473:pathology*; D055815:Young Adult