title: Head and neck squamous cell carcinoma: differentiation of histologic grade with standard- and high-b-value diffusion-weighted MRI.
abstract: BACKGROUND
  The correlation between the histologic grades and the apparent diffusion coefficient (ADC) in head and neck squamous cell carcinomas (HNSCCs) remains unclear. This study aimed to evaluate the potential of diffusion-weighted MRI (DW-MRI) at both standard and high b values to differentiate the histologic grades of HNSCC.
  
  
  METHODS
  In all, 54 consecutive patients with HNSCCs (34 well-differentiated, 10 moderately differentiated, and 10 poorly differentiated) performed DW-MRIs at both b = 1000 and 2000 s/mm(2) prior to biopsy or surgery. The ADC values were compared among the different histologic grades.
  
  
  RESULTS
  The ADC values of well-differentiated and poorly differentiated HNSCC were significantly different at both b values (p < .001 in both). However, significant difference between moderately differentiated and poorly differentiated HNSCC was revealed at only b = 2000 s/mm(2) (p = .014).
  
  
  CONCLUSIONS
  DW-MRIs at standard and high b values are helpful for differentiating histologic grades in HNSCC with better differentiation at a high b-value.
authors.affiliation: Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
authors.forename: Tae Jin
authors.initials: TJ
authors.lastname: Yun
authors.forename: Ji-hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Kwang Hyun
authors.initials: KH
authors.lastname: Kim
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Sohn
authors.forename: Sun-Won
authors.initials: SW
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck