Fast myocardial T₁ mapping using cardiac motion correction

To improve the efficiency of native and postcontrast high-resolution cardiac T₁ mapping by utilizing cardiac motion correction.

Common cardiac T₁ 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 T₁ mapping by integration of cardiac motion correction. Golden angle radial data was acquired continuously for 8 s with in-plane resolution of 1.3 × 1.3 mm² . 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 T₁ mapping. Native T₁ mapping was evaluated in healthy subjects. Furthermore, the technique was applied for postcontrast T₁ mapping in 5 patients with suspected fibrosis.

Cine images with high contrast were obtained, leading to robust cardiac motion estimation. Motion-corrected T₁ maps showed myocardial T₁ times similar to cardiac-triggered T₁ 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 T₁ maps, focal fibrosis could be confirmed with late contrast-enhancement images.

The proposed approach provides high-resolution T₁ maps within 8 s. Data acquisition efficiency for T₁ mapping was improved by a factor of 5 by integration of cardiac motion correction, resulting in precise T₁ maps.