An interventional instrument (30) having ultrasound sensors (S1, S2, S3, S4, . . . ) is tracked using an ultrasound imaging device (10) that acquires and displays a 2D ultrasound image of a visualization plane (18), and performs 2D ultrasound sweeps for a range of plane angles (θ) obtained by rotating the ultrasound probe (12) and encompassing the visualization plane angle. For each ultrasound sensor, an optimal plane is found based on its emitted signal strength over the range of plane angles, and the ultrasound sensor is located in its optimal plane by analyzing the sensor signal as a function of the timing of the beams fired by the ultrasound probe. These locations in their respective optimal planes are transformed to a 3D reference space using a transform (42) parameterized by plane angle, and a visual indicator is displayed of spatial information (T, L) for the interventional instrument generated from the locations of the one or more ultrasound sensors in the 3D reference space.