Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13550-018-0463-8/MediaObjects/13550_2018_463_Fig2_HTML.png)
Quantitation of microPET imaging reveals BM trafficking kinetics to the bone injury site. The percentage of 89Zr activity accumulated at the fracture site was quantified by setting a volume of interest on the acquired PET/CT images (a) and correcting for radioactive decay. As an internal control, 89Zr activity in the contralateral tibia was quantified. The BM cells highly accumulated at the fracture 1 day after the fracture generation in both the day 1-fracture (b) and day 0-fracture (c) schemes and gradually decreased thereafter. The BM cells preferentially accumulated at the fracture site compared to the contralateral control in both fracture models 1 day after the fracture generation (n = 4 in each group, ****p < 0.0001 and ***p < 0.001 with two-way repeated measure analysis of variance (ANOVA) with Sidak’s multiple comparisons test. The arrows indicate the timing of bone injury generation)