FIG. 1.
Coronal maximum intensity projections from three-dimensional data sets of diffusion-weighted images obtained from a normal adult receiving granulocyte colony-stimulating factor prior to stem cell harvest and donation to a sibling with leukemia: (a) Day 0 and (b) Day 5 of G-CSF administration. The signal from bone marrow in the axial skeleton is markedly increased, consistent with a change in both the apparent water fraction, from 0.44 ± 0.06 to 0.69 ± 0.04, and the T2 value of water in the marrow, from 43.7 ± 5.4 to 58.4 ± 4.9 msec. The spleen also increased in size, from 238 to 493 mm3. The white blood cell count underwent a sevenfold increase over the same time period. The results are consistent with bone marrow mobilization.