title: Diffusion-weighted magnetic resonance imaging for diagnosing malignant pulmonary nodules/masses: comparison with positron emission tomography.
abstract: BACKGROUND
  Recent developments of diffusion-weighted magnetic resonance imaging (DWI) make it possible to image malignant tumors to provide tissue contrast based on difference in the diffusion of water molecules among tissues, which can be measured by apparent diffusion coefficient (ADC) value. The aim of this study is to examine the usefulness of DWI for benign/malignant discrimination of pulmonary nodules/masses compared with F-fluorodeoxyglucose (FDG) positron emission tomography (PET).
  
  
  METHODS
  PET and DWI were carried out prospectively in 104 patients with 140 pulmonary nodules/masses before surgery. FDG uptake of each lesion was quantitatively measured by a contrast ratio of standard uptake value (SUV-CR) between the lesions and contralateral lung. Diffusion of water molecule in each lesion was quantitatively measured by a minimum ADC (ADC-min). The diagnostic results were compared between the two modalities.
  
  
  RESULTS
  The receiver operating characteristics curve showed cutoff values of the ADC-min and the SUV-CR for benign/malignant discrimination to be 1.1 x 10 mm/s and 0.37, respectively. DWI and PET showed sensitivities of 0.70 and 0.72 and specificities of 0.97 and 0.79, respectively. Although there was no significant difference in sensitivity between the two methods, DWI showed a significantly higher specificity than PET because of fewer false-positives for active inflammatory lesions (p = 0.03). The ADC-min and SUV-CR values showed a significant reverse correlation (r = -0.504, p < 0.001).
  
  
  CONCLUSIONS
  DWI may be able to be used in place of FDG-PET to distinguish malignant from benign pulmonary nodules/masses with fewer false-positive results compared with FDG-PET.
authors: Department of Thoracic Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
authors: Takeshi
authors: T
authors: Mori
authors: Hiroaki
authors: H
authors: Nomori
authors: Koei
authors: K
authors: Ikeda
authors: Koichi
authors: K
authors: Kawanaka
authors: Shinya
authors: S
authors: Shiraishi
authors: Kazuhiro
authors: K
authors: Katahira
authors: Yasuyuki
authors: Y
authors: Yamashita
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018196:Carcinoma, Adenosquamous / Q000175:diagnosis; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis; D003952:Diagnostic Imaging; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18