Partition coefficients for gadolinium chelates in the normal myocardium: Comparison of gadopentetate dimeglumine and gadobenate dimeglumine

Purpose: To evaluate the influence of contrast agents with different relaxivity on the partition coefficient (λ) and timing of equilibration using a modified Look‐Locker inversion recovery (MOLLI) sequence in cardiac magnetic resonance imaging (MRI). Materials and Methods: MOLLI was acquired in 20 healthy subjects (1.5T) at the mid‐ventricular short axis precontrast and 5, 10, 20, 25, and 30 minutes after administration of a bolus of 0.15 mmol/kg gadobenate dimeglumine (Gd‐BOPTA) ( n = 10) or gadopentetate dimeglumine (Gd‐DTPA) ( n = 10). T1 times were measured in myocardium and blood pool. λ was approximated by ΔR1 myocardium /ΔR1 blood . Values for Gd‐BOPTA and Gd‐DTPA were compared. Interobserver agreement was evaluated (intraclass correlation coefficient [ICC]). Results: T1 times of myocardium and blood pool ( P < 0.001) and λ (0.42 ± 0.03 and 0.47 ± 0.04, respectively, P < 0.001; excluding 5 minutes for Gd‐BOPTA) were significantly lower for Gd‐BOPTA than Gd‐DTPA. The λ (Gd‐DTPA) showed no significant variation between 5 and 30 minutes. The λ (Gd‐BOPTA) values were significantly lower at 5 minutes compared to other times (0.38 vs. 0.42; P < 0.05). Interobserver agreement for λ values was excellent with Gd‐BOPTA (ICC = 0.818) and good for Gd‐DTPA (ICC = 0.631). Conclusion: The λ (Gd‐BOPTA) values were significantly lower compared to λ (Gd‐DTPA) at the same administered dose. Using Gd‐BOPTA, the equilibrium between myocardium and blood pool was not achieved at 5 minutes postcontrast. J. Magn. Reson. Imaging 2012;36:733–737. © 2012 Wiley Periodicals, Inc.