title: Influence of spatial resolution and contrast agent dosage on myocardial T1 relaxation times.
abstract: OBJECTIVE
  Our aim was to study the influence of small variations in spatial resolution and contrast agent dosage on myocardial T1 relaxation time.
  
  
  METHODS
  Twenty-nine healthy volunteers underwent cardiovascular magnetic resonance at 3T twice, including a modified look-locker inversion recovery (MOLLI) technique-3(3)3(3)5-for T1 mapping. Native T1 was assessed in three spatial resolutions (voxel size 1.4 × 1.4 × 6, 1.6 × 1.6 × 6, 1.7 × 1.7 × 6 mm3), and postcontrast T1 after 0.1 and 0.2 mmol/kg gadobutrol. Partition coefficient was calculated based on myocardial and blood T1. T1 analysis was done per segment, per slice, and for the whole heart.
  
  
  RESULTS
  Native T1 values did not differ with varying spatial resolution per segment (p = 0.116-0.980), per slice (basal: p = 0.772; middle: p = 0.639; apex: p = 0.276), and globally (p = 0.191). Postcontrast T1 values were significantly lower with higher contrast agent dosage (p < 0.001). The global partition coefficient was 0.43 ± 0.3 for 0.2 and 0.1 mmol gadobutrol (p = 0.079).
  
  
  CONCLUSIONS
  Related to the tested MOLLI technique at 3T, very small variations in spatial resolution (voxel sizes between 1.4 × 1.4 × 6 and 1.7 × 1.7 × 6 mm3) remained without effect on the native T1 relaxation times. Postcontrast T1 values were naturally shorter with higher contrast agent dosage while the partition coefficient remained constant. Further studies are necessary to test whether these conclusions hold true for larger matrix sizes and in larger cohorts.
authors.affiliation: Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.|Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany.
authors.forename: Edyta
authors.initials: E
authors.lastname: Blaszczyk
authors.affiliation: Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.|Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Töpper
authors.affiliation: Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.|Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany.
authors.forename: Luisa
authors.initials: L
authors.lastname: Schmacht
authors.affiliation: Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.|Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Wanke
authors.affiliation: Siemens Healthcare GmbH, Erlangen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Greiser
authors.affiliation: Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.|Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany.
authors.forename: Jeanette
authors.initials: J
authors.lastname: Schulz-Menger
authors.affiliation: Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany. florian.von-knobelsdorff@charite.de.|Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany. florian.von-knobelsdorff@charite.de.
authors.forename: Florian
authors.initials: F
authors.lastname: von Knobelsdorff-Brenkenhoff
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003287:Contrast Media / Q000737:chemistry*; D005260:Female; D019786:Gadolinium DTPA; D064368:Healthy Volunteers; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D009942:Organometallic Compounds / Q000737:chemistry; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D019786:Gadolinium DTPA
keywords: Cardiac; Contrast agent; Spatial resolution; T1 mapping