title: Intraindividual comparison of T1 relaxation times after gadobutrol and Gd-DTPA administration for cardiac late enhancement imaging.
abstract: OBJECTIVE
  To evaluate T1-relaxation times of chronic myocardial infarction (CMI) using gadobutrol and gadopentetate dimeglumine (Gd-DTPA) over time and to determine the optimal imaging window for late enhancement imaging with both contrast agents.
  
  
  METHODS
  Twelve patients with CMI were prospectively included and examined on a 1.5 T magnetic resonance (MR) system using relaxivity-adjusted doses of gadobutrol (0.15 mmol/kg) and Gd-DTPA (0.2 mmol/kg) in random order. T1-relaxation times of remote myocardium (RM), infarcted myocardium (IM), and left ventricular cavity (LVC) were assessed from short-axis TI scout imaging using the Look-Locker approach and compared intraindividually using a Wilcoxon paired signed-rank test (α<0.05).
  
  
  RESULTS
  Within 3 min of contrast agent administration (CA), IM showed significantly lower T1-relaxation times than RM with both contrast agents, indicating beginning cardiac late enhancement. Differences between gadobutrol and Gd-DTPA in T1-relaxation times of IM and RM were statistically not significant through all time points. However, gadobutrol led to significantly higher T1-relaxation times of LVC than Gd-DTPA from 6 to 9 min (220 ± 15 ms vs. 195 ± 30 ms p<0.01) onwards, resulting in a significantly greater ΔT1 of IM to LVC at 9-12 min (-20 ± 35 ms vs. 0 ± 35 ms, p<0.05) and 12-15 min (-25 ± 45 ms vs. -10 ± 60 ms, p<0.05). Using Gd-DTPA, comparable ΔT1 values were reached only after 25-35 min.
  
  
  CONCLUSIONS
  This study indicates good delineation of IM to RM with both contrast agents as early as 3 min after administration. However, we found significant differences in T1 relaxation times with greater ΔT1 IM-LVC using 0.15 mmol/kg gadobutrol compared to 0.20 mmol/kg Gd-DTPA after 9-15 min post-CA suggesting earlier differentiability of IM and LVC using gadobutrol.
authors.affiliation: Department of Cardiology, Charité - Universitätsmedizin Berlin, Charité Campus Benjamin Franklin, Berlin, Germany. Electronic address: Patrick.doeblin@charite.de.
authors.forename: Patrick
authors.initials: P
authors.lastname: Doeblin
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany. Electronic address: rene.schilling@charite.de.
authors.forename: Rene
authors.initials: R
authors.lastname: Schilling
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany. Electronic address: moritz.wagner@charite.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany. Electronic address: renyluhur@yahoo.com.
authors.forename: Reny
authors.initials: R
authors.lastname: Luhur
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany; Imaging Science Institute, Charité, Berlin, Germany. Electronic address: alexander.huppertz@charite.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Huppertz
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany. Electronic address: bernd.hamm@charite.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany. Electronic address: matthias.taupitz@harite.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Taupitz
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany. Electronic address: tahir.durmus@charite.de.
authors.forename: Tahir
authors.initials: T
authors.lastname: Durmus
mesh_terms: D002908:Chronic Disease; D003287:Contrast Media / Q000008:administration & dosage; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009203:Myocardial Infarction / Q000473:pathology*; D009942:Organometallic Compounds / Q000008:administration & dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D019786:Gadolinium DTPA
keywords: Gadobutrol; Gadopentetate dimeglumine; Late enhancement; MRI; Myocardial infarction; T1 relaxation time