The Raytheon CK722 Junction Transistor, shown at the top of this old photograph, was the first mass-produced transistor and was manufactured in 1953.¹

      In 1954, Bell Laboratories built the first 'Second Generation Computer' containing transistors. The more complex the circuits became, however, the more complicated and numerous were the soldered connections between transistors, and the likelihood of faulty wiring increased.³⁷

      In 1958, Jack St. Clair Kilby of Texas Instruments, manufactured the first integrated circuit or chip. This minimised the faulty wiring problem of transistor circuits by connecting the tiny transistors during chip manufacture. The diminished distance between the transistors dramatically increased the speed of computers as well. The only connections needed were between the chips and other electronic components.³⁸

      Also in 1958, Anger replaced the film-screen combination with a single, large field-of-view NaI(Tl) crystal and photomultiplier tube (PMT) assembly. This resulted in far greater detection efficiency. The PMT array, combined with electronic position logic circuitry, determined the location of each scintillation event as it occurred in the crystal.¹⁰

      In addition to this, the energy of the scintillations could be analysed and if outside a predetermined energy range, could be excluded from further calculation and cathode ray tube (CRT) display. The CRT display showed a pattern of light that corresponded to the scintillations occurring in the detector crystal. These brighter flashes of light were more easily recorded photographically. This improved resolution, and reduced the time of acquisition and the radiation dose required. The images were recorded on Polaroid^® Film or on x-ray film, which was attached to the camera housing.¹⁰