title: Diffusion tensor imaging of deep gray matter in children treated for brain malignancies.
abstract: OBJECTIVE
  Previous DTI studies reported microstructural changes in white matter of patients receiving treatment for brain malignancies. The primary aim of this prospective pilot longitudinal study was to examine if DTI can detect microstructural changes in deep gray matter (as evaluated by the apparent diffusion coefficient, ADC) between pediatric patients treated with cranial radiation therapy and typically developing healthy children. The relationship between ADC and neurobehavioral performance was also examined.
  
  
  METHODS
  ADC was measured at 1.5 T in the caudate, putamen, globus pallidus, thalamus, and hippocampus in nine patients (mean age 11.8 years) and nine age-matched healthy controls. The study was designed with four visits: baseline, 6-month, 15-month, and 27-month follow-ups.
  
  
  RESULTS
  Patients had 24 % higher overall mean ADC in the hippocampus compared with controls (p = 0.003). Post hoc analyses revealed significantly elevated ADC at baseline (p = 0.003) and at the 27-month follow-up (p = 0.006). Nevertheless, patients performed normally on a verbal memory test considered to be a hippocampus-related function. Relative to controls, patients' performance on the tests of the visual-spatial working memory decreased over time (group by visit, p = 0.036). Both patients and controls showed a decline in motor speed with increasing ADC in the globus pallidus and putamen.
  
  
  CONCLUSIONS
  Childhood brain malignancies and their treatment may affect gray matter microstructure as measured by water diffusion. Significant findings in the hippocampus but not other regions suggest that differences in tissue sensitivity to disease- and treatment-related injury among gray matter regions may exist. ADC in basal ganglia may be associated with motor performance.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Division of Neuroradiology, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA, ahorska@jhmi.edu.
authors.forename: Alena
authors.initials: A
authors.lastname: Horská
authors.forename: Anna
authors.initials: A
authors.lastname: Nidecker
authors.forename: Jarunee
authors.initials: J
authors.lastname: Intrapiromkul
authors.forename: Firouzeh
authors.initials: F
authors.lastname: Tannazi
authors.forename: Siamak
authors.initials: S
authors.lastname: Ardekani
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Brant
authors.forename: Moody
authors.initials: M
authors.lastname: Wharam
authors.forename: E Mark
authors.initials: EM
authors.lastname: Mahone
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D016371:Cranial Irradiation / Q000009:adverse effects; D056324:Diffusion Tensor Imaging; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000528:radiation effects*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008137:Longitudinal Studies; D008297:Male; D010865:Pilot Projects