The continuous technological development now allow to use many new ultrasound applications, such as color and power Doppler technique, the elastosonography evaluation, the use of contrast media, and specifically the potentiality of 3D volume rendering also with 4D real-time images. This technology is still fairly difficult in normal use, according to a considerable experience in both anatomic and clinical biomechanics needed by the operator, and in particular in relation to the complexity of images reconstruction and possibly identification. The use of such methods should not be routinely, but is extremely useful in certain diseases and in specific districts such as in particular the hand, wrist and foot. The MRI investigation certainly allows a omprehensive and defined assessment of the pathological picture, and we believe that the use of 3D-4D US examination should be an exercise to develop the capacity of the operator to that method. The volume reconstruction is elective in cases where MRI investigation is not able to get a comprehensive diagnosis, as is in case of particular capsular ligament injuries, such as small joints tendon and cartilage, especially of the hand and foot fingers. This method also allows the use of 4D, which is basically a real time dynamic volumetric reconstruction, thereby further defined in relation to the static MRI examination. The iconography of these images today has nothing to envy to the three-dimensional CT reconstructions, resulting equally elegant both for didactic purposes that in any congress presentation. It is to be hoped that the ongoing technological developments will allow in the next future a more simple and rapid method which can be used in routine use. Prof. Giuseppe Monetti.