An implant centering system includes a sensor connected to a hollow cylindrical anchor via at least two struts. The hollow cylindrical anchor is transformable between a radially compressed configuration for delivery and a radially expanded configuration for lodging against a vessel wall. The struts longitudinally relocate the sensor between a first position in which the sensor is longitudinally spaced apart from the radially compressed anchor, and a second position in which the sensor is at least partially within a lumen of the radially expanded anchor and radially centered within vessel. In one embodiment, the struts are heat-set into a curved configuration and an externally applied force longitudinally relocates the sensor until the struts lock over center into their heat-set configuration. In another embodiment, radial expansion of the anchor longitudinally relocates the sensor without an externally applied force.