The Center for Diagnostic Imaging (CDI) has launched a positron emission tomography (PET) scanning program at its St. Louis Park Center (Minnesota) location. Brent Bullis, M.D., is heading the program.. . .Laser Diagnostic Technologies, developers of the GDx -- technology for detecting and tracking glaucoma by measuring the retinal nerve fiber layer, the tissue affected by glaucoma -- announced it has shipped its 2,500th glaucoma detection instrument.