Methods and apparatuses are disclosed for positioning a valve or other device in a patients body (e.g., in the patients heart) using an ultrasound system in combination with position sensors. One position sensor is mounted in the ultrasound probe so that a geometric relationship between the position sensor and the ultrasound transducer is known, and another position sensor is mounted in the device installation apparatus so that a geometric relationship between the position sensor and the device is known. The devices position with respect to the imaging plane is determined based on the detected positions of the position sensors and the known geometric relationships. Images of the imaging plane are displayed, and an indication of the devices position with respect to the imaging plane is outputted.