A catheter for positioning a valve during a transcatheter aortic valve replacement is formed from a resilient hollow body conformable to a guide wire when a guide wire is passed in through an upper opening in the hollow body and through the hollow body. When the guide wire is retracted, the catheter deploys to form a substantially straight upper shaft portion that extends downwardly from the upper opening and a distal ring perpendicular to the upper shaft portion. The distal ring approximates the size and shape of the patient's aortic valve annulus. An outer surface of the distal ring is radiopaque, and the distal ring comprises openings for dispersing radio opaque medium used in imaging. The deployed catheter is retracted until it snugly contacts the aortic valve annulus. The distal ring will be viewed as a straight line when the x-ray C-arm is properly aligned with the aortic valve annulus.