The relaxivities of 3 macrocyclic gadolinium-based contrast agents (GBCAs) were determined in human plasma and blood under standardized and clinically relevant laboratory conditions.
The T1 relaxivity, r1, was determined in human plasma at 1.5, 3, and 7 T, and in human blood at 3 T at 37°C in phantoms containing 4 different concentrations of the macrocyclic GBCAs gadobutrol, gadoteridol, and gadoterate. An inversion recovery turbo spin echo sequence was used to generate images with several inversion times. The T1-times were obtained by fitting the signal intensities to the signal equation. r1 was obtained by a 1/y-weighted regression of the T1-rates over the concentration of the GBCAs.
For gadobutrol, the obtained r1 [L/(mmol·s)] in human plasma at 1.5 T, 3 T, and 7 T, and in human blood at 3 T was 4.78 ± 0.12, 4.97 ± 0.59, 3.83 ± 0.24, and 3.47 ± 0.16. For gadoteridol, r1 was 3.80 ± 0.10, 3.28 ± 0.09, 3.21 ± 0.07, and 2.61 ± 0.16, and for gadoterate, 3.32 ± 0.13, 3.00 ± 0.13, 2.84 ± 0.09, and 2.72 ± 0.17.
The relaxivity of gadobutrol is significantly higher than that of gadoteridol and gadoterate at all magnetic field strengths and in plasma as well as in blood, whereas that of gadoteridol was higher than gadoterate only in plasma at 1.5 and 7 T. This is in accordance with results from 3 previous studies obtained in different media.
From the *MR Centre - Highfield MR, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
†Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
‡Bayer AG, Berlin, Germany
§Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
∥University Medical School of Saarland, Department of Gynecology, Obstetrics, and Reproductive Medicine, Homburg/Saar, Germany
¶Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna
#Austrian Cluster for Tissue Regeneration, Austria.
Received for publication January 31, 2019; and accepted for publication, after revision, April 6, 2019.
Conflicts of interest and sources of funding: The authors P.S., I.M.N.-H., and S.T. declare no conflicts of interest. The authors M.R., T.F., G.J., J.E. and H.P. are employees of Bayer AG. This study was funded by the Vienna Science and Technology Fund (WWTF-LS11-018), Austrian Science Fund (FWF KLI541-B30), and Slovak Grant Agency (APVV-15-0029). Financial support to the Medical University of Vienna was also provided by Bayer AG.
Correspondence to: Siegfried Trattnig, MD, MR Centre-Highfield MR, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Waerhringer Guertel 18-20, A-1090 Vienna, Austria. E-mail: email@example.com.
Online date: May 23, 2019