title: Magnetic resonance imaging of pulmonary nodules: accuracy in a granulomatous disease-endemic region.
abstract: OBJECTIVE
  To estimate the diagnostic accuracy of signal intensity of the lesion-to-spinal cord ratio (LSR) and apparent diffusion coefficient (ADC) in diffusion-weighted (DW) magnetic resonance imaging of pulmonary nodules suspicious for lung cancer in granulomatous lung disease-endemic regions.
  
  
  METHODS
  Forty-nine patients with indeterminate solitary pulmonary nodules detected by chest computed tomography and histopathologically confirmed diagnoses were included in the study. DW images were analysed semiquantitatively by focusing regions of interest on the lesion and spinal cord at the same level (for LSR calculation). ADCs were estimated from ratios of the two image signal intensities. Ratios of T1 and T2 signal intensity between nodules and muscle were calculated for comparison.
  
  
  RESULTS
  Mean ADCs ± standard deviations for lung cancer and benign lesions were 0.9 ± 0.2 and 1.3 ± 0.2 × 10(-3) mm(2)/s, respectively. Mean LSRs were 1.4 ± 0.3 for lung cancer and 1 ± 0.1 for benign lesions. ADCs and LSRs differed significantly between malignant and benign lesions (P < 0.001). Mean T2 signal intensity ratios also differed significantly between benign and malignant lesions (0.8 ± 0.2 vs. 1.6 ± 0.2; P < 0.05).
  
  
  CONCLUSIONS
  DWI can help to differentiate malignant from benign lesions according to ADC and the LSR with good accuracy.
  
  
  CONCLUSIONS
  • DW imaging can help differentiate malignant from benign pulmonary nodules. • ADC and LSR signal intensities had only small overlap between malignant and benign pulmonary nodules. • Mean T2 signal intensity ratios differed significantly between benign and malignant lesions.
authors.affiliation: University of Caxias do Sul, Caxias do Sul, 95070-560, Brazil. naticoncatto@hotmail.com.|, Rua 20 de setembro, 1487, 02, CEP 95020450, Caxias do Sul, Rio Grande do Sul, Brazil. naticoncatto@hotmail.com.
authors.forename: Natália
authors.initials: N
authors.lastname: Henz Concatto
authors.affiliation: Medical Imaging Research Laboratory, Federal University of Health Sciences of Porto Alegre, Porto Alegre, 90050-170, Brazil.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Watte
authors.affiliation: Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-901, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Marchiori
authors.affiliation: Department of Radiology, Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool, L14 3PE, UK.
authors.forename: Klaus
authors.initials: K
authors.lastname: Irion
authors.affiliation: Department of Thoracic Surgery, Santa Casa Hospital Complex, Porto Alegre, 90020-090, Brazil.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Felicetti
authors.affiliation: Department of Thoracic Surgery, Santa Casa Hospital Complex, Porto Alegre, 90020-090, Brazil.
authors.forename: José Jesus
authors.initials: JJ
authors.lastname: Camargo
authors.affiliation: Department of Radiology, Santa Casa Hospital Complex, Porto Alegre, 90020-090, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Hochhegger
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D019353:Endemic Diseases; D005260:Female; D006099:Granuloma; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D055613:Multiple Pulmonary Nodules / Q000000981:diagnostic imaging* / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D013118:Spinal Cord Diseases; D014057:Tomography, X-Ray Computed
keywords: Differentiation of malignant from benign lesions; Diffusion weighted; Granulomatous disease-endemic region; Magnetic resonance imaging; Pulmonary nodules