title: [Imaging characteristics of CT, MRI of tumors involving skull base in the parapharyngeal space].
abstract: OBJECTIVE
  To discuss imaging characteristics of CT, MRI of tumors involving skull base in the parapharyngeal space,maximatily limit and improve the diagnosis rate of tumors involving skull base in the parapharyngeal space.
  
  
  METHODS
  Thirty-one patients with tumors involving skull base in the parapharyngeal space treated in our department were collected and reviewed. All the patients have pathological diagnosis and were examined by CT and/or MRI. To explore shape of tumor, its relation with surrounding structures, CT shows density size and the MRI signal directly through retrospective analysis of imaging characteristics of CT, MRI.
  
  
  RESULTS
  In all the 31 cases, 19 tumors were schwannoma, 8 tumors were mixed tumor of salivary gland, 2 tumors were carotid body tumor. 2 tumors were nasopharyngeal carcinoma involving skull base. Schwannomas and salivary gland mixed tumor can be expressed as round or oval with periphery smooth, and had intact capsule. The tumors had necrosis, sac variable area. Pleomorphic adenoma are all derived from deep parotid. Schwannoma had clear boundary with deep parotid. The effect of cavum nasopharyngeal and cavum oropharyngeal is relevant to tumor sizes and locations. Imaging characteristics of CT, MRI for carotid body tumor show soft tissue mass with attenuation similar to that of muscle. CT enhancement scan show intense enhancement. MRI show imaging of flowing empty vein. Imaging characteristics of MRI for nasopharyngeal carcinoma involving skull base in the parapharyngeal space show oval mass with low density signal, T1WI enhancement scan show necrosis, sac variable area.
  
  
  CONCLUSIONS
  CT and MRI could provide the position, size, boundary of the tumor and its relationship with cervical blood vessels well, which were important to operation schemes. CT and MRI before operation are valuable to the treatment of PPS tumors.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Huang
authors.forename: Yehai
authors.initials: Y
authors.lastname: Liu
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Hu
authors.forename: Cahngyu
authors.initials: C
authors.lastname: Yao
authors.forename: Chaobing
authors.initials: C
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Yifan
authors.initials: Y
authors.lastname: Li
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010610:Pharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D012189:Retrospective Studies; D019292:Skull Base Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed