title: Diffusion-weighted magnetic resonance imaging of head and neck  squamous cell carcinomas.
abstract: OBJECTIVE
  To evaluate whether diffusion-weighted imaging (DWI) is a reliable technique to quantify microstructural differences between head and neck squamous cell carcinomas (SCC) and tumour-free soft tissue.
  
  
  METHODS
  DWI was obtained from 20 patients with histologically proven, untreated head and neck SCC. DWI was acquired using a diffusion-weighted, navigated echo-planar imaging sequence with a maximum b-value of 800 s/mm2. For an objective assessment of image quality, the signal-to-noise ratio (SNR) was calculated. Microstructural differences between vital tumour tissue and tumour-free soft tissue were quantified by calculating the apparent-diffusion-coefficients (ADC) on a pixel by pixel method.
  
  
  RESULTS
  Echo-planar DWI provided good image quality in all patients (mean SNR 18.4). The mean ADC of SCC, (0.64+/-0.28 x 10(-3) mm2/s), was significantly (P<0.0001) lower than that of the tumour-free soft tissue, (2.51+/-0.82 x 10(-3) mm2/s).
  
  
  CONCLUSIONS
  DWI is a reliable diagnostic tool to quantify the microstructural differences between vital tumour tissue and tumour-free soft tissue in patients with head and neck SCC.
authors.affiliation: Medical University Vienna, Department of Radiology, Division of MSK- and Neuroradiology, Waehringer Guertel 18-20, A-1090 Vienna, Austria. klaus.friedrich@meduniwien.ac.at
authors.forename: Klaus M
authors.initials: KM
authors.lastname: Friedrich
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Matzek
authors.forename: Stephan
authors.initials: S
authors.lastname: Gentzsch
authors.forename: Irene
authors.initials: I
authors.lastname: Sulzbacher
authors.forename: Christian
authors.initials: C
authors.lastname: Czerny
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Herneth
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity