The objective of this work was to determine the potential clinical usefulness of SPECT to image 511-keV annihilation photons.A triple-headed gamma camera equipped with ultra-high-energy collimators was used to image 18F. Sensitivity measurements were carried out and the FWHM and FWTM were determined in air and for a unit-density scattering medium. Additionally, tomographic phantom studies were acquired to evaluate image quality.The sensitivities of the three cameras were, for all practical purposes, identical. At a source-to-collimator distance of 100 mm, the FWHM and FWTM were 13 and 29 mm, respectively. A tomographic phantom study demonstrated that spheres with a diameter of 20 mm were well resolved when filled with 18F activity and placed inside a water-filled phantom.The triple-headed SPECT camera in this investigation is a practical means of acquiring tomographic 18F images. The reconstructed slices were of sufficient quality to be of value in some clinical studies.