title: Value of diffusion-weighted MR imaging using various parameters for assessment and characterization of solitary pulmonary nodules.
abstract: OBJECTIVE
  To determine the appropriate parameters and evaluation method for characterizing solitary pulmonary nodules (SPNs) using quantitative parameters of diffusion-weighted imaging (DWI).
  
  
  METHODS
  Thirty-two subjects with 36 SPNs underwent DWI with seven different b values (0, 50, 100, 150, 300, 500, and 1000s/mm(2)). Five quantitative parameters were obtained from the region of interest drawn over each SPN: apparent diffusion coefficients (ADCs), true diffusion coefficients (DCs), and perfusion fractions (PFs), and signal-intensity ratios between lesion and spinal cord from DWI (b values: 1000 [LSR1000] and 500 [LSR500)]). All quantitative parameters and the diagnostic capabilities were statistically compared.
  
  
  RESULTS
  SPNs were diagnosed as follow: malignant (n=27) and benign (n=9). Parameter comparisons for malignant and benign showed both LSRs differed significantly (p<0.05). Applying feasible threshold values showed LSR500 specificity (88.9% [8/9]) and accuracy (77.8% [28/36]) were significantly higher than ADC, DC, and PF specificity and accuracy (p<0.05). LSR1000 accuracy (72.2% [26/36]) was significantly higher than DC accuracy, and its specificity (88.9% [8/9]) was significantly higher than ADC, DC, and PF specificities (p<0.05).
  
  
  CONCLUSIONS
  For quantitative differentiation of SPNs, LSR evaluation was more useful and practical than ADC, DC, and PF, and choice of b values showed little impact for the differentiation.
authors.affiliation: Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: hkoyama@med.kobe-u.ac.jp.
authors.forename: Hisanobu
authors.initials: H
authors.lastname: Koyama
authors.affiliation: Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohno
authors.affiliation: Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Seki
authors.affiliation: Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Mizuho
authors.initials: M
authors.lastname: Nishio
authors.affiliation: Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshikawa
authors.affiliation: Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Sumiaki
authors.initials: S
authors.lastname: Matsumoto
authors.affiliation: Department of General Thoracic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Maniwa
authors.affiliation: Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Tomoo
authors.initials: T
authors.lastname: Itoh
authors.affiliation: Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nishimura
authors.affiliation: Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000473:pathology*
keywords: Diffusion magnetic resonance imaging; Lung neoplasms; Magnetic resonance imaging; Solitary pulmonary nodule