title: Spin lock and magnetization transfer imaging of head and neck tumors.
abstract: OBJECTIVE
  To evaluate and compare the spin lock and magnetization transfer techniques in the differentiation of benign and malignant head and neck tumors at magnetic resonance (MR) imaging.
  
  
  METHODS
  Forty consecutive patients with histologically verified head and neck tumors (20 malignant and 20 benign tumors, including five infections) were studied with a 0.1-T MR unit. The spin lock and magnetization transfer effects were defined as 1-(signal intensity with stronger preparation pulse/signal intensity with weaker preparation pulse).
  
  
  RESULTS
  A strong correlation between the spin lock and magnetization transfer effects was found (r = 85, P < .001). With a spin lock effect of 0.48 and a magnetization transfer effect of 0.32 as the thresholds, sensitivity for detecting a malignant tumor was 95% and 94%, respectively, and specificity was 60% and 65%.
  
  
  CONCLUSIONS
  Low spin lock and magnetization transfer effects are characteristic of benign tumors. High spin lock and magnetization transfer effects were associated with malignancy, but there were overlapping values for salivary gland infections, some benign tumors, and malignancies. The spin lock technique seems to be an effective method for generating magnetization transfer-based contrast in the head and neck tumors.
authors.affiliation: Department of Radiology, Helsinki University Central Hospital, University of Helsinki, Finland.
authors.forename: A T
authors.initials: AT
authors.lastname: Markkola
authors.forename: H J
authors.initials: HJ
authors.lastname: Aronen
authors.forename: T
authors.initials: T
authors.lastname: Paavonen
authors.forename: E
authors.initials: E
authors.lastname: Hopsu
authors.forename: L M
authors.initials: LM
authors.lastname: Sipilä
authors.forename: J I
authors.initials: JI
authors.lastname: Tanttu
authors.forename: R E
authors.initials: RE
authors.lastname: Sepponen
mesh_terms: D003937:Diagnosis, Differential; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012468:Salivary Gland Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity