Pack cementation is a type of chemical vapor deposition process that is widely used as a means to deposit diffusion coatings on metallic substrates. Pack cementation was used to deposit Ti on Ni wires of 75 and 100 µm initial diameter such that, upon homogenization, hollow near-equiatomic NiTi microtubes were created. In-situ synchrotron X-ray tomography was performed on these Ni wires during Ti deposition. A series of 750 radiographs were acquired over 180° rotation of the sample at an interval of 5 minutes for the entire duration of the coating process. To perform the tomographic measurements, a single Ni wire surrounded by the appropriate pack powder mixture was encapsulated in a quartz capillary under vacuum and a resistive heating furnace was lowered over the sample. Due to an imbalance of Ni and Ti intrinsic diffusivities during Ti deposition and subsequent interdiffusion, there is a net flux of vacancies toward the radial center of the wire. This leads to a local supersaturation of vacancies which condense to form discrete Kirkendall pores that eventually coalesce into a channel near the center of the wire. The phase and Kirkendall pore evolution were tracked throughout the deposition process. Based on analysis of the tomography data, the pore volume fraction varied in a cyclic nature over the duration of the experiment, likely due to a competition between pore growth and sintering as observations of some pores appearing to shift toward the wire surface were made.