Abstract: An imaging catheter apparatus can include an elongate shaft assembly having a proximal shaft portion and a distal shaft portion. The shaft assembly can be configured to carry an imaging transducer such that the imaging transducer is locatable at or near a distal portion of the elongate shaft assembly. At least one coupler can be attached to the elongate shaft assembly. The at least one coupler configured to permit an end user to at least one of couple or attach at least one of a guidewire or an interventional medical device to the elongate shaft assembly via the at least one coupler. For example, the at least one coupler can include an elastic sleeve. The elastic sleeve can expand to accommodate passage of a guidewire or interventional medical device therethrough. Then, the elastic sleeve can relax or shrink to grip the interventional medical device, such as to secure or stabilize its position with respect to the imaging catheter, such as for performing a medical procedure.