Quantitative stem cell imaging with magnetic particle imaging

MPI stem cell imaging - sensitivity and linearity: 9 pelletized, labeled hESC-derived cell populations (Fig. 2A) with varying cell numbers were imaged successively in the FFL imager. Fig. 2B shows the maximum image intensity from each reconstructed cell pellet image as a function of cell number. When a linear fit was applied, we found a strong linear correlation between MPI signal intensity and cell number, with R² > 0.99. Additionally, the detection sensitivity of the projection MPI system was found to be slightly over 10⁴ cells. We found no detectable MPI signal from unlabeled cell populations. Mice imaging: A MPI image of postmortem cell injections containing 4×10⁵ and 6×10⁵ is shown in Fig. 2C. The MPI image shows excellent contrast with minimal tissue effects. Additionally, the ratio of total MPI signal between the 6×10⁵ and 4×10⁵ injection regions was found to be 1.5, as expected.