title: Tissue characterization of head and neck lesions using diffusion-weighted MR imaging with SPLICE.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the usefulness of diffusion-weighted (DW) MR imaging with split acquisition of fast spin-echo signals (SPLICE) in the tissue characterization of head and neck mass lesions.
  
  
  METHODS
  DW MR images of 67 head and neck mass lesions were obtained using SPLICE with b-factors of 0 and 771s/mm(2). The lesions were classified into three categories: 16 cysts, 32 benign tumors, and 19 malignant tumors. After ADC maps were constructed for all lesions, ADC values were calculated and compared among the three categories.
  
  
  RESULTS
  No case showed severe image distortion on DW MR imaging with SPLICE, and reliable ADC maps and ADC values were obtained in all cases. The mean ADC value of cysts was 2.41+/-0.48 x 10(-3)mm(2)/s, which was significantly higher than that of benign (1.48+/-0.62 x 10(-3)mm(2)/s) and malignant (1.23+/-0.45 x 10(-3)mm(2)/s) tumors (P<0.001). However, there was no significant difference between the ADC values of benign and malignant tumors (P=0.246). When an ADC value of 2.10 x 10(-3)mm(2)/s or higher was used as the diagnostic criterion for cysts, the sensitivity, specificity, and accuracy were 94%, 88%, and 90%, respectively.
  
  
  CONCLUSIONS
  SPLICE was considered a recommended DW MR imaging technique for the head and neck. Although ADC values were useful in differentiating cysts from tumors, they contributed little in predicting malignancy.
authors.affiliation: Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. sakaorad@tmd.ac.jp
authors.forename: Junichiro
authors.initials: J
authors.lastname: Sakamoto
authors.forename: Norio
authors.initials: N
authors.lastname: Yoshino
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Okochi
authors.forename: Akiko
authors.initials: A
authors.lastname: Imaizumi
authors.forename: Akemi
authors.initials: A
authors.lastname: Tetsumura
authors.forename: Kazuto
authors.initials: K
authors.lastname: Kurohara
authors.forename: Tohru
authors.initials: T
authors.lastname: Kurabayashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult