title: Fuzzy C-means clustering of magnetic resonance imaging on apparent diffusion coefficient maps for predicting nodal metastasis in head and neck cancer.
abstract: OBJECTIVE
  The present study evaluated and analyzed apparent diffusion coefficients (ADCs) from partitions through a fuzzy C-means (FCM) technique for distinguishing nodal metastasis in head and neck cancer.
  
  
  METHODS
  MRI studies of 169 lymph node lesions, dissected from 22 patients with a histopathologically confirmed lymph node status, were analyzed using in-house software developed using MATLAB(®) (The MathWorks(®) Inc., Natick, MA). A radiologist manually contoured the lesions, and ADCs for each lesion were divided into two (low and high) and three (low, intermediate and high) partitions by using the FCM clustering algorithm.
  
  
  RESULTS
  The results showed that the low-value ADC clusters were more sensitive (95.7%) in distinguishing malignant from benign lesions than the whole-lesion mean ADC values (78.3%), while retaining a high specificity (approximately 90%). Moreover, receiver-operating characteristic curves demonstrated that the low-value ADC clusters used as a predictor of malignancy for lymph nodes could achieve a higher area under the curve (0.949 and 0.944 for two and three partitions, respectively).
  
  
  CONCLUSIONS
  The segmentation by ADC values of lesions through the FCM technique enables the efficient characterization of the lymph node pathology and can help distinguish malignant from benign lymph nodes.
  
  
  CONCLUSIONS
  Tumour heterogeneity may degrade the prediction of metastatic lymph nodes that involves using mean region-of-interest ADC values. The clustering of ADC values in lesions by using FCM can improve the diagnostic accuracy of nodal metastasis and reduce interreader variance.
authors.affiliation: 1 Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.|2 Department of Medical Imaging, Changhua Christian Hospital, Changhua, Taiwan.|3 Department of Medical Imaging and Radiological Science, Central Taiwan University of Science and Technology, Taichung, Taiwan.
authors.forename: Ming-Che
authors.initials: MC
authors.lastname: Lee
authors.affiliation: 1 Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Keh-Shih
authors.initials: KS
authors.lastname: Chuang
authors.affiliation: 4 Superintendent's Office, Changhua Christian Hospital, Changhua, Taiwan.
authors.forename: Mu-Kuan
authors.initials: MK
authors.lastname: Chen
authors.affiliation: 2 Department of Medical Imaging, Changhua Christian Hospital, Changhua, Taiwan.
authors.forename: Chi-Kuang
authors.initials: CK
authors.lastname: Liu
authors.affiliation: 2 Department of Medical Imaging, Changhua Christian Hospital, Changhua, Taiwan.
authors.forename: Kwo-Whei
authors.initials: KW
authors.lastname: Lee
authors.affiliation: 5 Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.|6 Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taoyuan, Taiwan.|7 Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Hui-Yu
authors.initials: HY
authors.lastname: Tsai
authors.affiliation: 1 Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.|6 Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Hsin-Hon
authors.initials: HH
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity