An ultrasound system has an ultrasound transducer equipped with a position marker and a needle equipped with a position marker. The position markers allow the position and orientation of the transducer and needle to be determined. Displays indicating a projection of the longitudinal axis of the needle onto a plane of an ultrasound image acquired via the transducer and displays indicating a projection of a reference position onto a plane of an ultrasound image acquired via the transducer are provided. Displays indicating in real-time whether the needle is substantially within the plane of the ultrasound image are provided.
