Fig. 2

Ho quantification in a subcutaneous VX-2 bearing rabbit. Rabbit 2. a Tumour before injection. The tumour is segmented with a yellow dotted line. The white arrow shows a rib. The rib is also visible in b. b Tumour after injection with accumulations of Ho microspheres, visible as white dots, indicated with white arrows. c A different axial slice shows the effect of inadvertent injection of air (black void inside the tumour). d Histogram of HU values of the entire tumour before and after injection of ¹⁶⁶Ho microspheres. The large negative (left of peak) and positive tail (right of peak) are caused by a relatively small number of voxels with injected air or Ho, respectively