Mini-Tablet application Regular digital imaging (DICOM) viewing software, commonly used in clinics, to evaluate radiological imaging, integrates simple measurement tools (e.g. distance or angle measurements). This technique is used to define a trajectory with an entry point at the frontal paramedian convexity towards the foramen of Monroe in a coronal section. Then, measurements can be taken to determine the angle between the trajectory and the respective tangent at the entry point on the skull surface. An I-Phone (Apple Inc., USA) software application available is used, importing anonymous imaging material. This image should be a coronal section with the lateral ventricles shown at the level of the anterior commissure. The next step is to define a paramedian entry point on the surface of the skull by tapping the finger on the respective spot. Then, the two feet are virtually placed on the skull surface. A rectangular trajectory orientation of the tube is then shown as a dotted line and can be shifted if necessary. The angle deviation from a rectangular insertion is then given by the software as a value. In addition, the finger may be placed on the target within the ventricle, and the length of the catheter will be given as distance value. As alternative, the CT scan (at the level : coronal section with the lateral ventricles shown at the level of the anterior commissure) can be photographed and used for angle calculations.