title: Is diffusion-weighted MRI useful for differentiation of small non-necrotic cervical lymph nodes in patients with head and neck malignancies?
abstract: OBJECTIVE
  To evaluate the usefulness of measuring the apparent diffusion coefficient (ADC) in diffusion-weighted magnetic resonance imaging to distinguish benign from small, non-necrotic metastatic cervical lymph nodes in patients with head and neck cancers.
  
  
  METHODS
  Twenty-six consecutive patients with head and neck cancer underwent diffusion-weighted imaging (b value, 0 and 800 s/mm(2)) preoperatively between January 2009 and December 2010. Two readers independently measured the ADC values of each cervical lymph node with a minimum-axial diameter of ≥ 5 mm but < 11 mm using manually drawn regions of interest. Necrotic lymph nodes were excluded. Mean ADC values were compared between benign and metastatic lymph nodes after correlating the pathology.
  
  
  RESULTS
  A total of 116 lymph nodes (91 benign and 25 metastatic) from 25 patients were included. Metastatic lymph nodes (mean ± standard deviation [SD], 7.4 ± 1.6 mm) were larger than benign lymph nodes (mean ± SD, 6.6 ± 1.4 mm) (p = 0.018). Mean ADC values for reader 1 were 1.17 ± 0.31 × 10(-3) mm(2)/s for benign and 1.25 ± 0.76 × 10(-3) mm(2)/s for metastatic lymph nodes. Mean ADC values for reader 2 were 1.21 ± 0.46 × 10(-3) mm(2)/s for benign and 1.14 ± 0.34 × 10(-3) mm(2)/s for metastatic lymph nodes. Mean ADC values between benign and metastatic lymph nodes were not significantly different (p = 0.594 for reader 1, 0.463 for reader 2).
  
  
  CONCLUSIONS
  Measuring mean ADC does not allow differentiating benign from metastatic cervical lymph nodes in patients with head and neck cancer and non-necrotic, small lymph nodes.
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea. ; Department of Radiology, Soonchunhyang University Hospital, Seoul 140-743, Korea.
authors.forename: Hyun Kyung
authors.initials: HK
authors.lastname: Lim
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Baek
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Namkug
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Hayoung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Jee Won
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Sang Yoon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Kyung Ja
authors.initials: KJ
authors.lastname: Cho
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
authors.forename: Jung Hwan
authors.initials: JH
authors.lastname: Baek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D010361:Patients; D011859:Radiography; D012680:Sensitivity and Specificity
keywords: Diffusion weighted imaging; Head and neck cancer; Lymph node; Metastasis