[New approaches to 3D-ultrasonographic imaging of infant hips].

Ultrasound of the infant hip is an established method in the diagnosis and monitoring of the treatment of congenital dysplasia of the hip (CDH). Its use as a screening method for CDH, early diagnosis and start of therapy results in a high success rate and reduces the length of the therapy. According to Graf's technique, the examination findings are taken from a standard plane. Assessment of the examined hip joint is based on information obtained from this standard intersection plane, which has to be representative for the whole joint configuration. Furthermore, the method according to Graf requires a very expert examiner. We report on a new approach to three dimensional ultrasound of the infant hip for covering and demonstrating the complete dimensions of CDH. A maturity disorder of the infant hip located outside the standard plane should be recognized by 3D ultrasound. In contrast to already existing 3D ultrasound systems with specially constructed transducers, we use a position sensor which, in conjunction with a video tape recorder, an external computer and the corresponding software, is able to support normal ultrasound equipment. A common 7.5 or 5 Mhz linear transducer can be used. During the examination, the form and size of the femoral head is automatically analysed. The result is placed as a virtual sphere into the 3D data set. The quality of the examination should be independent of the examiner's skill.