title: Enhancement of anatomical structures and detection of metastatic cervical lymph nodes: comparison of two different contrast material doses.
abstract: OBJECTIVE
  To determine if a 20 % reduction in the contrast material dose is acceptable in the CT evaluation of patients with head and neck malignancy.
  
  
  METHODS
  Sixty consecutive patients (mean age 67 years) with head and neck malignancy underwent contrast-enhanced CT according to two different protocols: protocol A (80 mL of contrast material administered at an injection rate of 1.5 mL/s) and protocol B (100 mL at 1.9 mL/s). The enhancement of anatomical structures and detectability of metastatic nodes were compared between the two protocols. Pathologic analysis of the surgical resection served as the reference standard.
  
  
  RESULTS
  CT numbers of the anatomical structures were not significantly different between the two protocols. Mean sensitivity (64 and 77 % for protocols A and B, respectively), specificity (78 and 84 %), and accuracy (74 and 83 %) tended to be higher for protocol B than for A, but no significant difference was found.
  
  
  CONCLUSIONS
  Reducing the contrast material dose by 20 % did not significantly impair the enhancement of anatomical structures or the detection of metastatic cervical lymph nodes. Radiologists should therefore consider reducing the contrast material dose used in head and neck CT.
authors.affiliation: Department of Radiology, Gifu Central Hospital, 3-25 Kawabe, Gifu 501-1198, Japan. haruwow860@yahoo.co.jp
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanematsu
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kato
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kojima
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Miyoshi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Goshima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kondo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawada
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Noda
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Moriyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000556:secondary; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media