Ulrike I. Attenberger MD, Presenter: Nothing to Disclose

Val Murray Runge MD, Abstract Co-Author: Research grant, Bracco Group Research grant, Bayer AG

Jonathan Martin Williams MD, Abstract Co-Author: Nothing to Disclose

Henrik Jakob Michaely MD, Abstract Co-Author: Consultant, Bayer AG

To evaluate intra-individual tumor enhancement at 1.5 T, using gadobutrol (Gadovist), a non-ionic, macrocyclic chelate, in comparison with both an ionic macrocyclic chelate, gadoterate meglumine (Dotarem), and an ionic linear chelate, gadopentetate dimeglumine (Magnevist) in a brain glioma model, and to quantitate the increase in tumor enhancement at 3 T compared to 1.5 T using gadobutrol.

23 rats, divided into two groups with n=16 and n=7, were evaluated. Group 1 evaluated gadobutrol relative to gadopentetate dimeglumine and gadoterate meglumine at 1.5 T. Each animal received gadobutrol and one of the comparators, with the two MR exams separated by 24 hours and the order of injection randomized. Group 2 compared results with gadobutrol at 1.5 and 3 T. T1-weighted scans were acquired pre-contrast and for 5 consecutive two-minute intervals post-contrast, using a contrast dose of 0.1 mmol/kg in each instance.

In group 1, tumor SNR and CNR were higher for gadobutrol compared to both other agents at each time point post contrast. The improvement in tumor CNR with gadobutrol, depending on time, was between 12 and 40% vs gadopentetate dimeglumine, with the difference statistically significant only at 7 min. The improvement in tumor CNR, depending on time, was between 19 and 27% vs gadoterate meglumine, with the difference statistically significant at 5 and 9 min. In group 2, the improvement in tumor SNR and CNR seen with the increase in field strength from 1.5 to 3 T for gadobutrol was statistically significant at all acquired time points (P < 0.002), with markedly higher SNR and CNR values at 3 T. CNR mean values ranged from 10.4±2.9 to 24.6±5.0 at 1.5 T and from 20.5±5.9 to 47.8±15.7 at 3 T, depending upon time point post-contrast.

Consistently greater tumor enhancement was noted at all time points post contrast for gadobutrol compared to both gadopentetate dimeglumine and gadoterate meglumine at 1.5 T, due to its higher intrinsic relaxivity, with a substantial further improvement in tumor enhancement noted using gadobutrol at 3 T as opposed to 1.5 T.

Gadobutrol, a macrocyclic chelate with superior stability compared to linear agents, demonstrates improved lesion enhancement due to higher T1 relaxivity and is recommended for imaging at 1.5 and 3 T.

Attenberger, U, Runge, V, Williams, J, Michaely, H, Evaluation of Gadobutrol, a Macrocyclic, Nonionic Gd Chelate in a Brain Glioma Model: Comparison with Gadoterate Meglumine and Gadopentetate Dimeglumine at 1.5 T, Combined with an Assessment of Field Strength Dependence, Specifically 1.5 vs 3 T.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007242.html