Fast myocardial T1 mapping using cardiac motion correction

Purpose To improve the efficiency of native and postcontrast high-resolution cardiac T-1 mapping by utilizing cardiac motion correction. Methods Common cardiac T-1 mapping techniques only acquire data in a small part of the cardiac cycle, leading to inefficient data sampling. Here, we present an approach in which 80% of each cardiac cycle is used for T-1 mapping by integration of cardiac motion correction. Golden angle radial data was acquired continuously for 8 s with in-plane resolution of 1.3 x 1.3 mm(2). Cine images were reconstructed for nonrigid cardiac motion estimation. Images at different TIs were reconstructed from the same data, and motion correction was performed prior to T-1 mapping. Native T-1 mapping was evaluated in healthy subjects. Furthermore, the technique was applied for postcontrast T-1 mapping in 5 patients with suspected fibrosis. Results Cine images with high contrast were obtained, leading to robust cardiac motion estimation. Motion-corrected T-1 maps showed myocardial T-1 times similar to cardiac-triggered T-1 maps obtained from the same data (1288 +/- 49 ms and 1259 +/- 55 ms, respectively) but with a 34% improved precision (spatial variation: 57.0 +/- 12.5 ms and 94.8 +/- 15.4 ms, respectively, P < 0.0001) due to the increased amount of data. In postcontrast T-1 maps, focal fibrosis could be confirmed with late contrast-enhancement images. Conclusion The proposed approach provides high-resolution T-1 maps within 8 s. Data acquisition efficiency for T-1 mapping was improved by a factor of 5 by integration of cardiac motion correction, resulting in precise T-1 maps.