title: Relationship between choline and apparent diffusion coefficient in patients with gliomas.
abstract: OBJECTIVE
  To examine the relationship between apparent diffusion coefficients (ADC) from diffusion weighted imaging (DWI) and choline levels from proton magnetic resonance spectroscopic imaging (MRSI) in newly diagnosed Grade II and IV gliomas within distinct anatomic regions.
  
  
  METHODS
  A total of 37 patients with Grade II and 28 patients with Grade IV glioma were scanned on a 1.5T system with 3D MRSI and DWI. Region level analysis included Spearman rank correlation between median normalized ADC and choline for each patient per grade within each distinct abnormal anatomical region. Voxel level analysis calculated a Spearman rank correlation per region, per patient.
  
  
  RESULTS
  Grade II lesions showed no evidence of a correlation between normalized ADC and choline using either the region or voxel level analysis. Region level analysis of Grade IV lesions did not appear to correlate in the contrast enhancement or necrotic core, but did suggest a significant negative correlation in the more heterogeneous nonenhancing and combined regions.
  
  
  CONCLUSIONS
  There appears to be differences in the relationship between ADC and choline levels in Grade II and Grade IV gliomas. Correlation within these regions in Grade IV lesions was strongest when all regions were included, suggesting heterogeneity may be driving the relationship.
authors.affiliation: University of California, San Francisco, California, USA. inas.khayal@radiology.ucsf.edu
authors.forename: Inas S
authors.initials: IS
authors.lastname: Khayal
authors.forename: Forrest W
authors.initials: FW
authors.lastname: Crawford
authors.forename: Suja
authors.initials: S
authors.lastname: Saraswathy
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: Lamborn
authors.forename: Susan M
authors.initials: SM
authors.lastname: Chang
authors.forename: Soonmee
authors.initials: S
authors.lastname: Cha
authors.forename: Tracy R
authors.initials: TR
authors.lastname: McKnight
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Nelson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000737:chemistry / Q000473:pathology*; D002794:Choline / Q000032:analysis*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005910:Glioma / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged
chemical_list: D002794:Choline