A multimodal intravascular catheter system includes a catheter with an optical channel and an electrical channel. A distal end of the catheter includes an optical element and an ultrasonic transducer, which are oriented orthogonally to a rotational axis of the catheter. A motor drive unit (MDU) is coupled to a proximal end of the catheter and includes a drive motor to rotate the catheter. The optical channel directs light from a pulsed UV laser source to the optical element, and returns an optical fluorescence signal from the optical element. A photodetector converts the returned optical fluorescence signal into an electrical fluorescence signal. An intravascular ultrasound (IVUS) processor is coupled to the ultrasonic transducer through the electrical channel, wherein the IVUS processor generates a drive signal for the ultrasound transducer, and processes echo information returned from the ultrasound transducer. Finally, a digitizer samples the electrical fluorescence signal and associated echo information.
