title: Hematopoietic marrow regeneration in pediatric patients undergoing spinal irradiation: MR depiction.
abstract: OBJECTIVE
  To evaluate changes in vertebral marrow signal intensity that occur over time in children undergoing craniospinal radiation therapy, specifically evaluating for the occurrence and timing of marrow regeneration.
  
  
  METHODS
  MR images of nine pediatric patients (ages 4 to 12 years) with posterior fossa medulloblastoma who received total spinal irradiation (24 to 40 Gy) and had at least three MR examinations were reviewed. Signal intensity to vertebral body marrow was graded by two pediatric neuroradiologists who were blinded to patient identity and to the timing of the studies.
  
  
  RESULTS
  Eight of nine patients demonstrated increasing signal intensity of the vertebral marrow after irradiation, consistent with conversion of hematopoietic to fatty marrow. In each of these patients, this was followed by subsequent decreasing signal intensity in a mottled or peripheral band pattern indicating recovery of hematopoietic marrow.
  
  
  CONCLUSIONS
  Changes in vertebral body signal intensity consistent with marrow reconversion commonly are seen in pediatric patients 11 to 30 months after they undergo total spinal irradiation.
authors.affiliation: Department of Radiology, University of Washington School of Medicine, Seattle, USA.
authors.forename: E C
authors.initials: EC
authors.lastname: Cavenagh
authors.forename: E
authors.initials: E
authors.lastname: Weinberger
authors.forename: D W
authors.initials: DW
authors.lastname: Shaw
authors.forename: K S
authors.initials: KS
authors.lastname: White
authors.forename: J R
authors.initials: JR
authors.lastname: Geyer
mesh_terms: D001853:Bone Marrow / Q000473:pathology / Q000528:radiation effects*; D002528:Cerebellar Neoplasms / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D016371:Cranial Irradiation / Q000009:adverse effects*; D005260:Female; D006410:Hematopoiesis / Q000528:radiation effects*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008527:Medulloblastoma / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000175:diagnosis*; D011879:Radiotherapy Dosage; D012038:Regeneration / Q000528:radiation effects*; D013131:Spine / Q000473:pathology / Q000528:radiation effects*