title: Follow-up CT and MR findings of osteoblastic spinal metastatic lesions after stereotactic radiotherapy.
abstract: OBJECTIVE
  We retrospectively analyzed pre and post-stereotactic radiotherapy CT and MRI findings and volume changes for osteoblastic spinal metastatic lesions.
  
  
  METHODS
  Of 114 lesions in 72 patients, 11 were osteoblastic. CT and MR images were reviewed to determine tumor volume, CT attenuation, T2 signal intensities, and contrast enhancement.
  
  
  RESULTS
  Tumor volume did not change for 10 lesions and increased for 1 lesion. CT attenuation increased for 8 lesions with heterogeneous T2 signal intensities. Of these 8 lesions, 4 had patterns of dark signal foci and the other 4 had patterns of both dark and bright signal foci. T2 signal intensity became heterogenous, with dark and bright foci, for 2 of 3 lesions for which CT attenuation decreased, and normalized for the third lesion. The degree of contrast enhancement decreased for 6 lesions and did not change for 5 lesions.
  
  
  CONCLUSIONS
  There were no changes in volume except for one case. On CT images, sclerotic changes were more common than loss of sclerotic foci. On T2-weighted images, dark signal intensities with or without bright signal foci developed and the degree of enhancement decreased for more than half of the cases.
authors.affiliation: Department of Radiology, College of Medicine, Inje University Ilsan Paik Hospital, 2240 Daehwa-dong, Ilsanseo-gu, Goyang-si, Gyeonggi-do 411-706, Republic of Korea. hyj@paik.ac.kr
authors.forename: Yoon Joon
authors.initials: YJ
authors.lastname: Hwang
mesh_terms: D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000000981:diagnostic imaging* / Q000473:pathology*; D016634:Radiosurgery; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000175:diagnosis* / Q000556:secondary / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA