title: Salivary gland tumors: evaluation with two-phase helical CT.
abstract: OBJECTIVE
  To evaluate two-phase helical computed tomography (CT) in the characterization of salivary gland tumors.
  
  
  METHODS
  Sixty-four patients with major salivary gland tumors underwent two-phase helical CT. The histopathologic diagnosis was obtained by means of surgical resection or biopsy in all patients. After the injection of 90 mL of contrast material at a rate of 3 mL/sec, helical CT scans were obtained at early and delayed phases with scanning delays of 30 and 120 seconds, respectively. The attenuation change and enhancement patterns in the tumors were assessed. The attenuation change in the tumor also was assessed quantitatively as the ratio of the CT number (in Hounsfield units) at delayed phase scanning to that at early phase scanning.
  
  
  RESULTS
  There were 35 pleomorphic adenomas, nine Warthin tumors, and 20 malignant tumors. Two-phase helical CT showed increase in attenuation in 30 (86%) pleomorphic adenomas, decrease in eight (89%) Warthin tumors, and increase in 11 (55%) and no change in eight (40%) malignant tumors at delayed phase scanning. A multinodular enhancement pattern was found in only 12 (34%) pleomorphic adenomas. The ratio of CT numbers was significantly different between Warthin tumors and pleomorphic adenomas and between Warthin tumors and malignant tumors.
  
  
  CONCLUSIONS
  The analysis of enhancement patterns by using two-phase helical CT will be helpful in the differential diagnosis of salivary gland tumors.
authors.affiliation: Department of Radiology, College of Medicine, Dongguk University, Pohang Hospital, Kyungsangbuk-Do, Korea.
authors.forename: D S
authors.initials: DS
authors.lastname: Choi
authors.forename: D G
authors.initials: DG
authors.lastname: Na
authors.forename: H S
authors.initials: HS
authors.lastname: Byun
authors.forename: Y H
authors.initials: YH
authors.lastname: Ko
authors.forename: C K
authors.initials: CK
authors.lastname: Kim
authors.forename: J M
authors.initials: JM
authors.lastname: Cho
authors.forename: H K
authors.initials: HK
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D010307:Parotid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D011856:Radiographic Image Enhancement; D013363:Submandibular Gland / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D013365:Submandibular Gland Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed