title: Imaging characteristics of metastatic chordoma.
abstract: OBJECTIVE
  Our aim was to describe the incidence and sites of metastatic chordomas and show their characteristic computed tomography (CT) and magnetic resonance (MR) findings.
  
  
  METHODS
  One hundred ninety-eight chordoma patients were registered in the institutional database and were followed up with CT and MR examinations for periods ranging from 1 to 158 months. Clinical features and CT and MR findings of metastatic chordomas were analyzed by two radiologists.
  
  
  RESULTS
  We counted 86 metastatic sites in 49 of 198 patients. The incidence of metastasis was 24.7 %. Sites of metastases were bone, lung, liver, lymph node, muscle, skin, pleura, cerebellum, cardiac muscle, pericardium, and adrenal gland. Duration from the diagnosis to the first detection of metastasis ranged from 0 to 600 months, with an average of 45.0 months. Osteolytic lesions were most common bone metastases, but osteosclerotic metastasis was also encountered. Metastatic chordoma showed very high intensity on diffusion-weighted (DW) images in 29 of 31 patients.
  
  
  CONCLUSIONS
  Metastases of chordoma are not rare and may occur several years after primary lesion presentation. The high intensity of DW images is characteristic and helpful for detecting metastatic chordoma.
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan. riwa@nirs.go.jp
authors.forename: Riwa
authors.initials: R
authors.lastname: Kishimoto
authors.forename: Tokuhiko
authors.initials: T
authors.lastname: Omatsu
authors.forename: Azusa
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Reiko
authors.initials: R
authors.lastname: Imai
authors.forename: Susumu
authors.initials: S
authors.lastname: Kandatsu
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kamada
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002817:Chordoma / Q000175:diagnosis* / Q000556:secondary*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media