title: Diagnostic Performance of Diffusion-Weighted Imaging for Multiple Hilar and Mediastinal Lymph Nodes with FDG Accumulation.
abstract: BACKGROUND
  It is sometimes difficult to assess patients who have multiple hilar and mediastinal lymph nodes (MHMLN) with FDG accumulation in PET-CT. Since it is uncertain whether diffusion-weighted magnetic resonance imaging (DWI) is useful in the assessment of such patients, its diagnostic performance was assessed.
  
  
  METHODS
  Twenty-three patients who had three or more stations of hilar and mediastinal lymph nodes with SUVmax of 3 or more in PET-CT were included in this study.
  
  
  RESULTS
  For diagnosis of disease, there were 20 malignancies (lung cancers 17, malignant lymphomas 2 and metastatic lung tumor 1), and 3 benign cases (sarcoidosis 2 and benign disease 1). For diagnosis of lymph nodes, there were 7 malignancies (metastasis of lung cancer 7 and malignant lymphoma 1) and 16 benign lymphadenopathies (pneumoconiosis/silicosis 7, sarcoidosis 4, benign disease 4, and atypical lymphocyte infiltration 1). The ADC value (1.57±0.29x10(-3) mm2/sec) of malignant MHMLN was significantly lower than that (1.99±0.24x10(-3) mm2/sec) of benign MHMLN (P=0.0437). However, the SUVmax was not significantly higher (10.0±7.34 as compared to 6.38±4.31) (P=0.15). The sensitivity (86%) by PET-CT was not significantly higher than that (71%) by DWI for malignant MHMLN (P=1.0). The specificity (100%) by DWI was significantly higher than that (31%) for benign MHMLN (P=0.0098). Furthermore, the accuracy (91%) with DWI was significantly higher than that (48%) with PET-CT for MHMLN (P=0.0129).
  
  
  CONCLUSIONS
  Evaluation by DWI for patients with MHMLN with FDG accumulation is useful for distinguishing benign from malignant conditions.
authors.affiliation: Department of Thoracic Surgery, Kanazawa Medical University, Ishikawa, Japan E-mail : usuda@kanazawa-med.ac.jp.
authors.forename: Katsuo
authors.initials: K
authors.lastname: Usuda
authors.forename: Sumiko
authors.initials: S
authors.lastname: Maeda
authors.forename: Nozomu
authors.initials: N
authors.lastname: Motono
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Ueno
authors.forename: Makoto
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Machida
authors.forename: Munetaka
authors.initials: M
authors.lastname: Matoba
authors.forename: Naoto
authors.initials: N
authors.lastname: Watanabe
authors.forename: Hisao
authors.initials: H
authors.lastname: Tonami
authors.forename: Yoshimichi
authors.initials: Y
authors.lastname: Ueda
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Sagawa
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008206:Lymphatic Diseases / Q000175:diagnosis*; D008207:Lymphatic Metastasis; D008223:Lymphoma / Q000473:pathology; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D064847:Multimodal Imaging; D011009:Pneumoconiosis / Q000175:diagnosis; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012507:Sarcoidosis / Q000175:diagnosis; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18