title: T1 Signal-Intensity Increase in the Dentate Nucleus after Multiple Exposures to Gadodiamide: Intraindividual Comparison between 2 Commonly Used Sequences.
abstract: Different T1-weighted sequences have been used for qualitative and quantitative evaluation of T1 signal intensity related to gadolinium deposition in the dentate nucleus in patients who underwent several enhanced MR imaging studies. Our purpose was to perform an intraindividual qualitative and quantitative comparison between T1-weighted spin-echo and 3D magnetization-prepared rapid acquisition of gradient echo sequences in patients who had multiple exposures to gadodiamide.
  
  
  
  Our retrospectively selected population included 18 patients who underwent at least 3 administrations of gadodiamide and had a baseline and a final MR imaging performed with both T1-weighted sequences. Qualitative and quantitative analyses were independently performed. Dentate nucleus/middle cerebellar peduncle signal-intensity ratios and signal changes between the baseline and final examinations were compared by using the Wilcoxon signed rank test. Correlation between quantitative and qualitative evaluations was assessed by using a polyserial correlation test.
  
  
  
  The differences between the 2 sequences for both baseline and last examination dentate nucleus/middle cerebellar peduncle ratios were statistically significant (P = .008 and P = .006, respectively); however, the signal-intensity changes of the ratios with time were not (P = .64). The correlation between the qualitative and quantitative analysis was very strong (near-perfect) (r = 0.9) for MPRAGE and strong (r = 0.63) for spin-echo sequences.
  
  
  
  T1-weighted spin-echo and MPRAGE sequences cannot be used interchangeably for qualitative or quantitative analysis of signal intensity in the dentate nucleus in patients who received gadodiamide. Baseline and final examination ratios should be evaluated across time by using the same sequence. Qualitative analysis performed with MPRAGE correlated better with quantitative analysis and may offer advantages over spin-echo sequences for research purposes.
authors.affiliation: From the Department of Radiology (J.R., M.R., M.A., R.H.N., M.C., R.C.S.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina Department of Neuroradiology (J.R.), Centro Hospitalar de Lisboa Central, Lisbon, Portugal Joana-Ramalho@netcabo.pt.
authors.forename: J
authors.identifier: 0000-0003-4067-0589
authors.initials: J
authors.lastname: Ramalho
authors.affiliation: From the Department of Radiology (J.R., M.R., M.A., R.H.N., M.C., R.C.S.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina Department of Radiology (M.R.), Hospital Garcia de Orta, Almada, Portugal.
authors.forename: M
authors.identifier: 0000-0003-2522-1670
authors.initials: M
authors.lastname: Ramalho
authors.affiliation: From the Department of Radiology (J.R., M.R., M.A., R.H.N., M.C., R.C.S.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina Department of Radiology (M.A.), King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: M
authors.identifier: 0000-0002-9081-0087
authors.initials: M
authors.lastname: AlObaidy
authors.affiliation: From the Department of Radiology (J.R., M.R., M.A., R.H.N., M.C., R.C.S.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina Division of Neuroradiology (R.H.N.), Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil.
authors.forename: R H
authors.identifier: 0000-0002-2483-964X
authors.initials: RH
authors.lastname: Nunes
authors.affiliation: From the Department of Radiology (J.R., M.R., M.A., R.H.N., M.C., R.C.S.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: M
authors.identifier: 0000-0003-2960-1064
authors.initials: M
authors.lastname: Castillo
authors.affiliation: From the Department of Radiology (J.R., M.R., M.A., R.H.N., M.C., R.C.S.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: R C
authors.identifier: 0000-0001-5773-8071
authors.initials: RC
authors.lastname: Semelka
mesh_terms: D000328:Adult; D000368:Aged; D002529:Cerebellar Nuclei / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA