Rather than high spatial resolution most of the plant biology
experiments require an imaging system to be highly sensitive.
In this area direct detection of emitted positrons holds a great
advantage compared to PET. Depending on the imaging object
we found the ratio of imaging efficiencies of direct positron to
PET detectors to vary from 650 to 1600. So in order to detect
and image low levels of activity, which are highly anticipated
in plant biology due to plant structures and short half-life of
radioisotopes used, direct positron detection method is favored.