Disclosed are embodiments relating to a process for reducing the total acid number of a hydrocarbon feed by contacting the feed with a metal titanate catalyst having an MTiO3 structure wherein M is a metal having a valence of 2+, resulting in a hydrocarbon product having a final total acid number lower than the initial total acid number of the feed. The combined plate carrier and refiner plate segment may be then attached to a refiner disk. The IVUS imaging system also includes an interface module removably coupled to the intravascular device.