Comparison of methods for determining the partition coefficient of gadolinium in the myocardium using T1 mapping.

PURPOSE: To develop and validate modified Look-Locker (MOLLI) protocols to generate myocardial T1 maps within clinically acceptable breath-hold durations and to compare partition coefficients (λ) of gadolinium (Gd)-DTPA determined from either bolus injection (BI) or continuous infusion (CI) techniques.
MATERIALS AND METHODS: T1 mapping was performed in phantoms and in 10 volunteers on a 1.5T scanner using the standard (3-3-5) MOLLI technique and two MOLLI schemes with shorter breath-hold durations. Imaging was performed precontrast and every 5 minutes following a bolus of 0.1 mmol/kg Gd-DTPA and a 15-minute delayed continuous infusion of 0.001 mmol/kg Gd-DTPA until equilibrium T1 in the myocardium was achieved to enable direct comparison of T1 relaxation times between techniques and λ's between the BI and CI methods.
RESULTS: There was good agreement of T1 values between the 3-3-5 standard MOLLI protocol and the modified 3-5 MOLLI protocol in both phantom studies over a range of heart rates and in human subjects. Both MOLLI protocols produced similar measurements of λ using both the BI and CI methods.
CONCLUSION: A reduced breath-hold MOLLI T1 mapping protocol combined with the BI method can accurately characterize T1 and λ in clinically applicable breath-hold durations without requiring a long equilibrium phase infusion.