title: Assessment of mediastinal tumors with diffusion-weighted single-shot echo-planar MRI.
abstract: OBJECTIVE
  To assess the role of diffusion-weighted single-shot echo-planar magnetic resonance imaging (MRI) in patients with mediastinal tumors.
  
  
  METHODS
  Prospective study was conducted on 45 consecutive patients (29 male, 16 female, age 22-66 years, mean 41 years) with mediastinal tumor. They underwent diffusion-weighted single-shot echo-planar MRI of the mediastinum with a b-factor of 0, 300, and 600 sec/mm(2). The apparent diffusion coefficient (ADC) value of the mediastinal tumor was correlated with the histopathological findings.
  
  
  RESULTS
  The mean ADC value of malignant mediastinal tumors was 1.09 +/- 0.25 x 10(-3) mm(2)/sec, and of benign tumors was 2.38 +/- 0.56 x 10(-3) mm(2)/sec. There was a significant difference in the mean ADC value between malignant and benign tumors (P = 0.001) and within different grades of malignancy (0.001). When an ADC value of 1.56 x 10(-3) mm(2)/sec was used as a threshold value for differentiating malignant from benign tumor, the best results were obtained with an accuracy of 95%, sensitivity of 96%, specificity of 94%, positive predictive value of 94%, negative predictive value of 96%, and area under the curve of 0.938.
  
  
  CONCLUSIONS
  The ADC value is a noninvasive parameter that can be used for differentiation of malignant from benign mediastinal tumors and grading of mediastinal malignancy.
authors.affiliation: Department of Diagnostic Radiology, Mansoura Faculty of Medicine, Mansoura, Egypt. arazek@mans.eun.eg
authors.forename: Ahmed Abdel
authors.initials: AA
authors.lastname: Razek
authors.forename: Ahmed
authors.initials: A
authors.lastname: Elmorsy
authors.forename: Mohsen
authors.initials: M
authors.lastname: Elshafey
authors.forename: Tamer
authors.initials: T
authors.lastname: Elhadedy
authors.forename: Osama
authors.initials: O
authors.lastname: Hamza
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008479:Mediastinal Neoplasms / Q000473:pathology*; D008482:Mediastinum / Q000473:pathology; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D055815:Young Adult