Fig. 3.

Relationships between retention of ⁶⁴Cu-ATSM and ⁶⁴Cu-Cl₂ and hypoxia. a Co-registration of ¹⁸F-FMISO PET signal (2 h post-injection) with ⁶⁴Cu-ATSM PET signal (3 h or 24 h post-injection). The overlaid images corresponds to 60% signal maximum or 5% signal abnormality for ⁶⁴Cu-ATSM (red), ¹⁸F-FMISO (green), or ⁶⁴Cu-ATSM/¹⁸F-FMISO merged (yellow). b ¹⁸F-FMISO and ⁶⁴Cu-ATSM uptake were evaluated at 2 h and 24 h after radiotracer injection, respectively. Quantification of ⁶⁴Cu-ATSM and ¹⁸F-FMISO uptake from ipsilateral (tumor) and contralateral (healthy brain) SUVs (left part) or ratio between tumor and contralateral SUVs (right part) at the different imaging points. Mean ± SD, n = 5 rats for ¹⁸F-FMISO and n = 3 rats for ⁶⁴Cu-ATSM. Tukey’s HSD test after significant two-ways ANOVA (radiotracer and ROI factors): **p < 0.01. c From same coronal rat brain sections performed 24 h after ⁶⁴Cu-ATSM or ⁶⁴Cu-Cl₂ injection, autoradiography and pimonidazole immunostaining were done to evaluate overlapping of these two labeling. Scale bar = 250 μm