Techniques are described that combine intravascular ultrasound (“IVUS”) and optical coherence tomography into a single catheter that utilizes a micro-motor driven imaging core for imaging of patient tissue, e.g., a blood vessel wall. In one example, an imaging assembly includes a catheter, an imaging core with a micro-motor, one or more transducer conductors, an optical coherence tomography apparatus, and one or more optical fibers in communication with the optical coherence tomography apparatus.