Abstract Intravascular ultrasound (IVUS) is a device that is surgically inserted into a femoral artery, or vein, to aid in the diagnosis of cardiovascular disease. Correctly locating the IVUS tip facilitates accurate 3D vascular reconstruction. Researchers are actively investigating different methods, such as: stereo X-rays, radio triangulation, computer-aided tomography (CAT) scans, etc., to produce quality 3D graphical vascular images. Each of these methods has their pros and cons, however they all require external sensors and some are bulky and complicated to operate.Abstract This research investigates an accelerometer, constructed from a multi-mode fiber-optic cable, and studies its performance with multi-mode fiber interferometry technology (speckle-gram analysis) and presents experimental evidence to support its suitability for tracking an IVUS sensor in vivo, leading to real-time 3D reconstruction of internal arterial segments. The system resulting from this study is expected to be simple, small, and economically feasible, to bridge the diagnostic/treatment time gap and eliminate the need for external tracking equipment. Non-linear models and analysis of variance methodologies are presented to verify that the fiber-optic accelerometer is functioning within experimental error which can provide accurate spatial tracking. The results from this study show that the fiber accelerometer is performing as well as a micro-electromechanical machine system (MEMS) accelerometer and, unlike the MEMS, it is immune to environmental noise. The potential system is expected to reduce the computation necessary to perform 3D vascular reconstruction from IVUS data, leading to improvements in, and the reduction of, the diagnostic/treatment time-line. Also, the performance and sensitivity of this novel positional sensor is expected to improve with appropriate changes in the craftsmanship of the fiber accelerometer and testing apparatus.