title: Advantages of diffusion-weighted imaging over positron emission tomography-computed tomography in assessment of hilar and mediastinal lymph node in lung cancer.
abstract: BACKGROUND
  The significance of diffusion-weighted imaging (DWI) is uncertain for the diagnosis of nodal involvement. The purpose of this study was to examine diagnostic capability of DWI compared with PET-CT for nodal involvement of lung cancer.
  
  
  METHODS
  A total of 160 lung cancers (114 adenocarcinomas, 36 squamous cell carcinomas, and 10 other cell types) were analyzed in this study. DWI and PET-CT were performed preoperatively.
  
  
  RESULTS
  The optimal cutoff values to diagnose metastatic lymph nodes were 1.70 × 10(-3) mm(2)/s for ADC value and 4.45 for SUVmax. DWI correctly diagnosed N staging in 144 carcinomas (90 %) but incorrectly diagnosed N staging in 16 (10 %) [3 (1.9 %) had overstaging, 13 (8.1 %) had understaging]. PET-CT correctly diagnosed N staging in 133 carcinomas (83.1 %) but incorrectly diagnosed N staging in 27 (16.8 %) [4 (2.5 %) had overstaging, 23 (14.4 %) had understaging]. Sensitivity, accuracy, and negative predictive value for N staging by DWI were significantly higher than those by PET-CT. Of the 705 lymph node stations examined, 61 had metastases, and 644 did not. The maximum diameter of metastatic lesions in lymph nodes were 3.0 ± 0.9 mm in 21 lymph node stations not detected by either DWI or PET-CT: 7.2 ± 4.1 mm in 39 detected by DWI, and 11.9 ± 4.1 mm in 24 detected by PET-CT. There were significant differences among them. The sensitivity (63.9 %) for metastatic lymph node stations by DWI was significantly higher than that (39.3 %) by PET-CT. The accuracy (96.2 %) for all lymph node stations by DWI was significantly higher than that (94.3 %) by PET-CT.
  
  
  CONCLUSIONS
  DWI has advantages over PET-CT in diagnosing malignant from benign lymph nodes of lung cancers.
authors.affiliation: Department of Thoracic Surgery, Kanazawa Medical University, Uchinada, Ishikawa, Japan. usuda@kanazawa-med.ac.jp
authors.forename: Katsuo
authors.initials: K
authors.lastname: Usuda
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Sagawa
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: Yasuaki
authors.initials: Y
authors.lastname: Kuginuki
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Yoshimichi
authors.initials: Y
authors.lastname: Ueda
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sakuma
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis*; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging