title: Value of diffusion-weighted MR imaging in the differentiation between benign and malignant cervical lymph nodes.
abstract: OBJECTIVE
  To evaluate echo-planar diffusion-weighted MR imaging (DWI) in the differentiation between benign and malignant cervical lymph nodes.
  
  
  METHODS
  35 consecutive patients with 55 enlarged (>10mm) cervical lymph nodes underwent MR imaging at 1.5-T. DWI was performed using a single-shot echo-planar (SSEPI) MR imaging sequence with b values (b: diffusion factor) of 0, 500 and 1000 s/mm(2). Apparent diffusion coefficient (ADC) maps were reconstructed for all patients and ADC values were calculated for each lymph node. Imaging results were correlated with histopathologic findings after neck dissection or surgical biopsy, findings in PET/CT or imaging follow-up. Mann-Whitney test was used for statistical analysis and a receiver operating characteristic (ROC) curve analysis was performed.
  
  
  RESULTS
  Cervical lymph node enlargement was secondary to metastases from squamous cell carcinomas [n=25], non-Hodgkin's lymphoma [n=6], reactive lymphadenitis [n=20], cat scratch lymphadenitis [n=2] and sarcoidosis [n= 2]. The mean ADC values (x10(-3) mm(2)/s) were 0.78+/-0.09 for metastatic lymph nodes, 0.64+/-0.09 for lymphomatous nodes and 1.24+/-0.16 for benign cervical lymph nodes. ADC values of malignant lymph nodes were significantly lower than ADC values of benign lymph nodes. 94.3% of lesions were correctly classified as benign or malignant using a threshold ADC value of 1.02 x 10(-3) mm(2)/s.
  
  
  CONCLUSIONS
  According to our first experience, DWI using a SSEPI sequence allows reliable differentiation between benign and malignant cervical lymph nodes.
authors.affiliation: Department of Radiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, D-81675 Munich, Germany. holzapfel@roe.med.tum.de
authors.forename: Konstantin
authors.initials: K
authors.lastname: Holzapfel
authors.forename: Sabrina
authors.initials: S
authors.lastname: Duetsch
authors.forename: Claudius
authors.initials: C
authors.lastname: Fauser
authors.forename: Matthias
authors.initials: M
authors.lastname: Eiber
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
authors.forename: Jochen
authors.initials: J
authors.lastname: Gaa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008206:Lymphatic Diseases / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult