Fig. 1.

Four major categories of measurement techniques can be defined for the determination of midline shift (MLS). (1) The (A/2-B) method, where A is the width of the intracranial space and B is the distance from the tabula interna to the septum pellucidum at the foramen of Monro, (2) the ideal midline A is determined as the line between the most anterior and posterior parts of the falx cerebri. Line B is drawn perpendicular to line A to the septum pellucidum and is then calculated as shift. Each measurement method can be combined with a different predefined measurement location