Right after the invention of first generation scanner in the late 1960s of the 20th century, the computed tomography (CT) technology had developed rapidly within 10 years later. The third generation scanner was introduced into the market in 1975 to solve the problem of measurement time of previous generations. In 1976, the first scanner of the fourth generation was available to solve the problem of object size, ring artifacts as well as the general stability of the third generation. Nowadays along with medical imaging, CT has been widely used in many fields with an increasing demand. CT is considered as the modern non-destructive testing tool that can be applied on object sizes ranging from millimeters to meters in many socioeconomic fields, including the inspection of currently running equipment and petrochemical towers. In Vietnam, Center for Applications of Nuclear Technique in Industry (CANTI) is one of very few organizations that has carried out the research, design and construction of industrial CT scanners. This paper presents the results on the research and manufacture of the hardware of the fourth generation CT scanner for inspecting large-sized industrial towers, the image reconstruction algorithms, and the most important, the geometric matrix for image recontruction. Test results on the laboratorial specimen is also presented in this paper