title: Improving CT-guided transthoracic biopsy of mediastinal lesions by diffusion-weighted magnetic resonance imaging.
abstract: OBJECTIVE
  To evaluate the preliminary results obtained using diffusion-weighted magnetic resonance imaging and the apparent diffusion coefficient for planning computed tomography-guided biopsies of selected mediastinal lesions.
  
  
  METHODS
  Eight patients with mediastinal lesions suspicious for malignancy were referred for computed tomography-guided biopsy. Diffusion-weighted magnetic resonance imaging and apparent diffusion coefficient measurement were performed to assist in biopsy planning with diffusion/computed tomography fused images. We selected mediastinal lesions that could provide discordant diagnoses depending on the biopsy site, including large heterogeneous masses, lesions associated with lung atelectasis or consolidation, lesions involving large mediastinal vessels and lesions for which the results of biopsy using other methods and histopathological examination were divergent from the clinical and radiological suspicion.
  
  
  RESULTS
  In all cases, the biopsy needle was successfully directed to areas of higher signal intensity on diffusion-weighted sequences and the lowest apparent diffusion coefficient within the lesion (mean, 0.8 [range, 0.6-1.1]×10-3 mm2/s), suggesting high cellularity. All biopsies provided adequate material for specific histopathological diagnoses of four lymphomas, two sarcomas and two thymomas.
  
  
  CONCLUSIONS
  Functional imaging tools, such as diffusion-weighted imaging and the apparent diffusion coefficient, are promising for implementation in noninvasive and imaging-guided procedures. However, additional studies are needed to confirm that mediastinal biopsy can be improved with these techniques.
authors.affiliation: Department of Imaging, AC Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Marcos Duarte
authors.initials: MD
authors.lastname: Guimarães
authors.affiliation: Department of Radiology, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Hochhegger
authors.affiliation: Department of Diagnostic Radiology, MD Anderson Cancer Center, University of Texas, Houston, TX, USA.
authors.forename: Marcelo Felipe Kuperman
authors.initials: MF
authors.lastname: Benveniste
authors.affiliation: Department of Diagnostic and Interventional Radiology, MD Anderson Cancer Center, University of Texas, Houston, TX, USA.
authors.forename: Bruno Calazans
authors.initials: BC
authors.lastname: Odisio
authors.affiliation: Department of Thoracic Surgery, AC Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Jefferson Luiz
authors.initials: JL
authors.lastname: Gross
authors.affiliation: Department of Interventional Radiology, AC Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Charles Edouard
authors.initials: CE
authors.lastname: Zurstrassen
authors.affiliation: Department of Imaging, AC Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Chiang Cheng
authors.initials: CC
authors.lastname: Tyng
authors.affiliation: Department of Imaging, AC Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Almir Galvão Vieira
authors.initials: AG
authors.lastname: Bitencourt
authors.affiliation: Department of Radiology, Universidade Federal do Rio de Janeiro, Petrópolis, RJ, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Marchiori
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D008297:Male; D008479:Mediastinal Neoplasms / Q000473:pathology*; D008482:Mediastinum / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden; D055815:Young Adult