Figure 6.

Well plate images. (a) Serial dilutions (130, 13 and 1.3 μCi) of ¹⁸F; exposure time 300 s, aperture setting f/1, large binning. Note the occurrence of occasional ‘hot pixels’—a background caused by direct interactions of 511 keV annihilation photons in the CCD. These remain after the system correction for cosmic ray interactions is applied. (b) Serial dilutions (100, 10 and 1 μCi) of ⁹⁰Y; exposure time 30 s, aperture setting f/1, large binning. Both images were acquired with the 15 cm field of view (position B). Note the different colour scales, as the ⁹⁰Y wells are much brighter. (The colour scale units of radiance are photons per second per square centimetre per steradian.)