The invention provides an intravascular catheter with an expandable member such as a balloon with an imaging device on a surface of the expandable member. The imaging device can use an optical fiber on a surface of the expandable member to image a treatment site. Since an image can be captured directly from the surface of the expandable member, an operator can examine the treatment site while positioning the expandable member. With the treatment site in view, the operator can deliver the treatment (e.g., inflate the balloon or deploy the stent) with confidence that it will be located properly.