UV-photons from an Xe-filled gas scintillation counter are detected with a CsI photocathode coupled to a double stage, low-pressure wire chamber. The high quantum efficiency, (9 pct), of the UV-detector yields a high detection efficiency of both primary and secondary scintillation photons. An energy resolution of 4.1 pct (FWHM) was recorded with 60 keV X-rays, inducing secondary scintillation in 5 bar of Xe; the wire chamber operated at 20 Torr of CH4. The two-dimensional planar localization of UV-photons, combined with the drift time measurement of primary electrons, provides a three-dimensional, multihit, imaging capability of X-ray photon interactions, with a resolution of 2-3 mm (FWHM). The stability of the CsI photocathode under different operation conditions and its sensitivity to exposure to air are discussed.