Abdominal T1 relaxation times at 7T

Abstract Objective To quantify the T 1 relaxation times at 7T for key abdominal organs and tissues, including the liver, kidney, spleen, and skeletal paraspinal muscles. Materials and methods T 1 mapping was performed on a 7T whole-body scanner with a parallel transmission (pTx) system in five healthy volunteers. Static pTx (B 1 + shimming) was applied to maximize B 1 + magnitude in the target region. For each T 1 map, data were collected using eight snapshot gradient-echo inversion recovery sequences during breath holding. Voxel-wise T 1 values were calculated based on DICOM data using exponential model fitting. Results Mean abdomen T 1 values and corresponding coefficients of variation across the group were: 1829 ± 60 ms, 3.3% for the kidney cortex; 2619 ± 83 ms, 3.2% for the kidney medulla; 1378 ± 48 ms, 3.5% for the liver; 1954 ± 28 ms, 1.4% for the skeletal paraspinal muscle; 1770 ± 36 ms, 2.0% for the spleen. Conclusion In this study, we quantified the T 1 relaxation times at 7T for key abdominal organs and tissues, including the liver, kidney, spleen, and skeletal paraspinal muscle. To achieve this, pTx was applied to mitigate B 1 + dropouts in the target regions. The B 1 + insensitive snapshot gradient-echo inversion recovery method was utilized to acquire accurate and reproducible T 1 maps.