The NIST phantom was acquired with a standard 3D Gradient Echo sequence (TR = 18 ms, TE = 10 ms, FA = 10 degree). Image matrix = 256 x 256 x 256, number of subvexels = 8 x 1 x 1. The total number of subvoxels (isochromats) was 25,579,520. The calculation time was  about 48 min.

The following cross-sections show horizontal (coronal) planes for the fiducial spheres, proton density standard spheres, T2 standard spheres, and T1 standard spheres.

 

Coronal cross-sections (1 mm interval):