title: Malignant pleural disease: diagnosis by using diffusion-weighted and dynamic contrast-enhanced MR imaging--initial experience.
abstract: OBJECTIVE
  To investigate the use of diffusion-weighted (DW) imaging for differentiating benign lesions from malignant pleural disease (MPD) and to retrospectively assess dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging acquisitions to find out whether combining these measurements with DW imaging could improve the diagnostic value of DW imaging.
  
  
  METHODS
  This study was approved by the local ethics committee, and all patients provided written informed consent. Thirty-one consecutive patients with pleural abnormalities suspicious for MPD underwent whole-body positron emission tomography (PET)/computed tomography (CT) and thorax MR examinations. Diagnostic thoracoscopy with histopathologic analysis of pleural biopsies served as the reference standard. First-line evaluation of each suspicious lesion was performed by using the apparent diffusion coefficient (ADC) calculated from the DW image, and the optimal cutoff value was found by using receiver operating characteristic curve analysis. Afterward, DCE MR imaging data were used to improve the diagnosis in the range of ADCs where DW imaging results were equivocal.
  
  
  RESULTS
  Sensitivity, specificity, and accuracy of PET/CT for diagnosis of MPD were 100%, 35.3%, and 64.5%. The optimal ADC threshold to differentiate benign lesions from MPD with DW MR imaging was 1.52 × 10(-3) mm(2)/sec, with sensitivity, specificity, and accuracy of 71.4%, 100%, and 87.1%, respectively. This result could be improved to 92.8%, 94.1%, and 93.5%, respectively, when DCE MR imaging data were included in those cases where ADC was between 1.52 and 2.00 × 10(-3) mm(2)/sec. A total of 20 patients had disease diagnosed correctly, nine had disease diagnosed incorrectly, and two cases were undetermined with PET/CT. DW imaging helped stage disease correctly in 27 patients and incorrectly in four. The undetermined cases at PET/CT were correctly diagnosed at MR imaging.
  
  
  CONCLUSIONS
  DW imaging is a promising tool for differentiating MPD from benign lesions, with high accuracy, and supplementation with DCE MR imaging seems to further improve sensitivity.
authors.affiliation: Department of Radiology, University Hospitals Leuven, Herestraat 49, B-3000 Leuven, Belgium. johan.coolen@uzleuven.be
authors.forename: Johan
authors.initials: J
authors.lastname: Coolen
authors.forename: Frederik
authors.initials: F
authors.lastname: De Keyzer
authors.forename: Philippe
authors.initials: P
authors.lastname: Nafteux
authors.forename: Walter
authors.initials: W
authors.lastname: De Wever
authors.forename: Christophe
authors.initials: C
authors.lastname: Dooms
authors.forename: Johan
authors.initials: J
authors.lastname: Vansteenkiste
authors.forename: Ilse
authors.initials: I
authors.lastname: Roebben
authors.forename: Eric
authors.initials: E
authors.lastname: Verbeken
authors.forename: Paul
authors.initials: P
authors.lastname: De Leyn
authors.forename: Dirk
authors.initials: D
authors.lastname: Van Raemdonck
authors.forename: Kristiaan
authors.initials: K
authors.lastname: Nackaerts
authors.forename: Steven
authors.initials: S
authors.lastname: Dymarkowski
authors.forename: Johny
authors.initials: J
authors.lastname: Verschakelen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D064847:Multimodal Imaging; D009942:Organometallic Compounds; D010997:Pleural Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013906:Thoracoscopy; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine