title: Diffusion-weighted MR imaging vs. multi-detector row CT: Direct comparison of capability for assessment of management needs for anterior mediastinal solitary tumors.
abstract: OBJECTIVE
  To evaluate and compare the capability of diffusion-weighted MR imaging (DWI) and CT for assessment of management needs for anterior mediastinal solitary tumors.
  
  
  METHODS
  Thirty-five patients with pathologically confirmed anterior mediastinal tumors were enrolled. The tumors were divided into two groups according to need for management: tumors not needing further intervention or treatment (group A; thymoma type A, AB and B1) and tumors needing further intervention and treatment (group B; other thymoma types and malignancies). The apparent diffusion coefficient (ADC) of each tumor was measured, and probabilities of malignancy and need for further intervention and treatment were visually assessed on CT. The differences in ADCs between group A and B and between malignancies and thymomas in group B were evaluated with the Mann-Whitney's U-test. Feasible threshold values for differentiation of group B from group A and distinguishing malignancies from thymomas assessed as group B were determined by the ROC-based positive test, and McNemar's test was used for comparing diagnostic capabilities of DWI with those of CT.
  
  
  RESULTS
  ADCs for the two groups were significantly different (p<0.001). Application of the threshold value for differentiation of group B from A showed no significant difference (p>0.05). Application of the feasible threshold value for distinguishing malignant from thymomas assessed as group B showed that specificity (76.9%) and accuracy (85.2%) of DWI were significantly better than those of visual score (p<0.05).
  
  
  CONCLUSIONS
  DWI has useful potential for the assessment of management needs for anterior mediastinum solitary tumors as well as CT.
authors.affiliation: Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: klfsiena@yahoo.co.jp.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Seki
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. Electronic address: yosirad@kobe-u.ac.jp.
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; Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: nmizuho@med.kobe-u.ac.jp.
authors.forename: Mizuho
authors.initials: M
authors.lastname: Nishio
authors.affiliation: Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Department of Diagnostic Radiology, Hyogo Cancer Center, Hyogo, Japan. Electronic address: daisuket@hp.pref.hyogo.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takenaka
authors.affiliation: Division of Thoracic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: maniwa@med.kobe-u.ac.jp.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Maniwa
authors.affiliation: Division of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: tomitoh@med.kobe-u.ac.jp.
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. Electronic address: nishiy@med.kobe-u.ac.jp.
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. Electronic address: sugimura@med.kobe-u.ac.jp.
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000328:Adult; D000368:Aged; D003933:Diagnosis; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008479:Mediastinal Neoplasms / Q000175:diagnosis* / Q000628:therapy*; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: CT; Diffusion-weighted imaging; MRI; Mediastinal neoplasm; Thorax