It is important for sonographers to be familiar with the anatomic structures they are imaging, as this allows them to choose the best route of approach. For instance, as the skull constitutes a barrier to ultrasounds, the transducer must be positioned in such a manner that it emits ultrasound through an acoustic window, i.e., a suture or a fontanel. The figure below gives a few examples of best routes of approach and indications for their use.