Figure 3.

Comparative in vivo NIS imaging indicates differences between the PET tracer [¹⁸F]BF₄ ⁻ and the SPECT tracer [¹²³I]iodide. Tumors were established as in Fig. 2 but grown to sizes of ~350 mm³ (see Supplementary Fig. S2B) before being imaged by either [¹⁸F]BF₄ ⁻-PET (a) or [¹²³I]iodide-SPECT (b). Dynamic PET data were binned into time intervals comparable to sequential SPECT images (see Materials and Methods). Al images are maximum intensity projections overlaid on CT. Abbreviations are: bladder (B), heart (H), kidney (K), stomach (S), thyroid and salivary glands (Th + SG), and primary tumor (T). Representative images of cohorts of N = 3 are shown.