title: Gadolinium retention in the dentate nucleus and globus pallidus is dependent on the class of contrast agent.
abstract: OBJECTIVE
  To compare changes in signal intensity (SI) ratios of the dentate nucleus (DN) and the globus pallidus (GP) to those of other structures on unenhanced T1-weighted magnetic resonance (MR) images between linear and macrocyclic gadolinium-based contrast agents (GBCAs).
  
  
  METHODS
  The study was approved by the ethical committee of the University of Heidelberg (reference no. S-324/2014). Owing to the retrospective character of the study, the ethical committee did not require any written informed consent. Two groups of 50 patients who underwent at least six consecutive MR imaging examinations with the exclusive use of either a linear GBCA (gadopentetate dimeglumine) or a macrocyclic GBCA (gadoterate meglumine) were analyzed retrospectively. The difference in mean SI ratios of DN to pons and GP to thalamus on unenhanced T1-weighted images from the last and first examinations was calculated. One-sample and independent-sample t tests were used to assess the difference in SI ratios for both groups, and regression analysis was performed to account for potential confounders.
  
  
  RESULTS
  The SI ratio difference in the linear group was greater than 0 (mean DN difference ± standard deviation, 0.0407 ± 0.0398 [P < .001]; GP, 0.0287 ± 0.0275 [P < .001]) and significantly larger (DN, P < .001 and standardized difference of 1.16; GP, P < .001 and standardized difference of 0.81) than that in the macrocyclic group, which did not differ from 0 (DN, 0.0016 ± 0.0266 [P = .680]; GP, 0.0031 ± 0.0354 [P = .538]). The SI ratio difference between the last and first examinations for the DN remained significantly different between the two groups in the regression analysis (P < .001).
  
  
  CONCLUSIONS
  This study indicates that an SI increase in the DN and GP on T1-weighted images is caused by serial application of the linear GBCA gadopentetate dimeglumine but not by the macrocyclic GBCA gadoterate meglumine. Clinical implications of this observation remain unclear.
authors.affiliation: From the Department of Neuroradiology, University of Heidelberg Medical Center, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany (A.R., L.D.W., O.E., S.B., P.K., S.H., M.B.); Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.R., H.P.S.); Department of Psychology, University of Mannheim, Mannheim, Germany (P.J.K.); and Neurology Clinic, University of Heidelberg, Heidelberg, Germany (W.W.).
authors.forename: Alexander
authors.initials: A
authors.lastname: Radbruch
authors.forename: Lukas D
authors.initials: LD
authors.lastname: Weberling
authors.forename: Pascal J
authors.initials: PJ
authors.lastname: Kieslich
authors.forename: Oliver
authors.initials: O
authors.lastname: Eidel
authors.forename: Sina
authors.initials: S
authors.lastname: Burth
authors.forename: Philipp
authors.initials: P
authors.lastname: Kickingereder
authors.forename: Sabine
authors.initials: S
authors.lastname: Heiland
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wick
authors.forename: Heinz-Peter
authors.initials: HP
authors.lastname: Schlemmer
authors.forename: Martin
authors.initials: M
authors.lastname: Bendszus
mesh_terms: D002529:Cerebellar Nuclei / Q000378:metabolism*; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D005917:Globus Pallidus / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine / Q000493:pharmacokinetics*; D008875:Middle Aged; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; D019786:Gadolinium DTPA; C072417:gadoterate meglumine