FIGURE 3.  (A) MIP slices of processed lung activity probability map obtained from corresponding SPECT study. Color bar indicates intensity for normalized activity probability. (B) Representative slice of lung density map obtained from 27-h SPECT/CT scan. Density map and activity probability maps are direct inputs for MCNP4b dose calculation. (C) ROIs of tumors in a representative transverse slice, generated by 3D-ID, are shown.