title: Vertebra disc ratio as a parameter for bone marrow involvement and its application in Gaucher disease.
abstract: OBJECTIVE
  To establish the vertebra disc ratio (VDR), the ratio of the average T1-weighted gray value of disc L3 and intervertebral disc L3/L4, as a parameter for bone marrow involvement. To explore its value as alternative for bone marrow fat fraction measured with Dixon Quantitative Chemical Shift Imaging (Ff) in Gaucher disease (GD).
  
  
  METHODS
  Age dependency and normal value for the VDR were determined in 46 controls. The VDR in untreated GD (n = 22) and long-treated GD (7.5 years; n = 19) were compared with it. The changes in VDR in treated (n = 33) and untreated (n = 8) GD were calculated. The correlation between VDR and Ff was determined.
  
  
  RESULTS
  Age dependency was small. The normal VDR was 1.90 +/- 0.30, both untreated GD (1.29 +/- 0.31) and long-treated GD (1.70 +/- 0.33) differed significantly from normal. Changes in treated GD were significant in the first four treatment years, in untreated GD they were not. The correlation with Ff was 0.86.
  
  
  CONCLUSIONS
  The VDR is a useful parameter for evaluation of bone marrow of patients with GD. The VDR correlates very well with Ff, so applicability is expected in diseases in which Ff has proven to be useful.
authors.affiliation: Department of Radiology, Academic Medical Center, Meibergdreef 9, G1-209, 1105 AZ Amsterdam, The Netherlands. E.J.Vlieger@amc.uva.nl
authors.forename: Erik-Jan P
authors.initials: EJ
authors.lastname: Vlieger
authors.forename: Mario
authors.initials: M
authors.lastname: Maas
authors.forename: Erik M
authors.initials: EM
authors.lastname: Akkerman
authors.forename: Carla E M
authors.initials: CE
authors.lastname: Hollak
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Den Heeten
mesh_terms: D000328:Adult; D000368:Aged; D001855:Bone Marrow Diseases / Q000209:etiology* / Q000473:pathology*; D005260:Female; D005776:Gaucher Disease / Q000150:complications*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013131:Spine / Q000473:pathology*