title: Initial experience of 3-tesla apparent diffusion coefficient values in characterizing squamous cell carcinomas of the head and neck.
abstract: BACKGROUND
  With the increased clinical use of 3-Tesla (3T) magnets, it becomes important to identify the potential applications of advanced magnetic resonance (MR) imaging techniques such as diffusion-weighted imaging in head and neck pathologies.
  
  
  OBJECTIVE
  To establish the 3T apparent diffusion coefficient (ADC) values for normal neck structures, and to examine the utility of ADC values in distinguishing head and neck squamous cell carcinomas (HNSCC) from normal neck anatomy.
  
  
  METHODS
  3T diffusion-weighted imaging was performed on 10 normal volunteers and 10 patients with known HNSCC. In the volunteers, mean ADC was calculated in the parotid gland, submandibular gland, base of the tongue, pterygoid muscle, masseter muscle, paraspinal muscles, true vocal cord, thyroid gland, thyroid cartilage, cricoid cartilage, and lymph nodes. The mean tumor ADC value was calculated from the 10 patients with HNSCC and compared with the normal ADC values from various neck structures.
  
  
  RESULTS
  The mean ADC value measured in the HNSCC was 1.101 (+/-0.214) x 10(-3) mm(2)/s. This was significantly lower than ADC values of paraspinal muscles, pterygoid muscle, masseter muscle, thyroid gland, and base of the tongue (P=0.0006, 0.0002, 0.0001, 0.001, and 0.002, respectively). The tumor ADC values were not significantly different from ADC values of parotid and submandibular glands (P=0.057 and 0.14, respectively).
  
  
  CONCLUSIONS
  3T ADC values show potential for distinguishing HNSCC from normal extracranial head and neck structures.
authors.affiliation: Department of Radiology, Division of Neuroradiology, University of Michigan Health System, Ann Arbor, Michigan 48109, USA. ashoks@med.umich.edu
authors.forename: A
authors.initials: A
authors.lastname: Srinivasan
authors.forename: R
authors.initials: R
authors.lastname: Dvorak
authors.forename: S
authors.initials: S
authors.lastname: Rohrer
authors.forename: S K
authors.initials: SK
authors.lastname: Mukherji
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000033:anatomy & histology