title: A five-colour colour-coded mapping method for DCE-MRI analysis of head and neck tumours.
abstract: OBJECTIVE
  To devise a method to convert the time-intensity curves (TICs) of head and neck dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data into a pixel-by-pixel colour-coded map for identifying normal tissues and tumours.
  
  
  METHODS
  Twenty-three patients with head and neck squamous cell carcinoma (HNSCC) underwent DCE-MRI. TIC patterns of primary tumours, metastatic nodes, and normal tissues were assessed and a program was devised to convert the patterns into a classified colour-coded map. The enhancement patterns of tumours and normal tissue structures were evaluated and categorized into nine grades (0-8) based on the predominance of coloured pixels on maps.
  
  
  RESULTS
  Five identified TIC patterns were converted into a colour-coded map consisting of red (maximum enhancement), brown (continuous slow rise-up), yellow (rapid wash-in and wash-out), green (rapid wash-in and plateau), and blue (rapid wash-in and rise-up). The colour-coded map distinguished all 21 primary tumours and 15 metastatic nodes from normal structures. Primary tumours and metastatic nodes were colour coded as predominantly yellow (grades 1-2) in 17/21 and 6/15, green (grades 3-5) in 3/21 and 5/15, and blue (grades 6-7) in 1/21 and 4/15, respectively. Vessels were coded red in 46/46 (grade 0) and muscles were coded brown in 23/23 (grade 8). Salivary glands, thyroid glands, and palatine tonsils were coded into predominantly yellow (grade 1) in 46/46 and 10/10 and 18/22, respectively.
  
  
  CONCLUSIONS
  DCE-MRI derived five-colour-coded mapping provides an objective easy-to-interpret method to assess the dynamic enhancement pattern of head and neck cancers.
authors.affiliation: Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong. jyuan@cuhk.edu.hk
authors.forename: J
authors.initials: J
authors.lastname: Yuan
authors.forename: S K K
authors.initials: SK
authors.lastname: Chow
authors.forename: D K W
authors.initials: DK
authors.lastname: Yeung
authors.forename: A D
authors.initials: AD
authors.lastname: King
mesh_terms: D000465:Algorithms; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D003116:Color; D003287:Contrast Media; D019786:Gadolinium DTPA; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA