OBJECT: The aim of this study was to demonstrate the anatomy of the quadrigeminal cistern, define the anatomic landmarks, and measure the extension of the cistern in the living by using magnetic resonance (MR) cisternography with 3-dimensional reconstruction.
METHODS: The quadrigeminal cistern was examined in 38 patients. We focused on measurements of the superior, posterior, and lateral limits; the anterior and posterior maximal rostrocaudal diameter; the distance between the right and left superior colliculus and the right and left inferior colliculus; and the angle between the quadrigeminal plate and pineal gland.
RESULTS: The highest variability was observed for the posterior rostrocaudal diameter with a standard deviation of 3.1 and a range from 8 to 21.1 mm followed by the anterior-posterior diameter with a standard deviation of 2.8 and a range from 6.4 to 16.5 mm. In all cases the distance between the right and left superior colliculus (13.3 ± 1.8 mm; mean ± SD) was longer than the distance between the right and left inferior colliculus (11.4 ± 1.3 mm; mean ± SD). We classified 2 types of cisterns: closed cisterns with angles between the quadrigeminal plate and the pineal gland ranging from 39° to 63° and open cisterns with angles ranging from 63° to 76°. The analysis of variability by age and sex showed no significant differences.
CONCLUSIONS: The MR cisternography with 3-dimensional reconstruction was a simple and noninvasive tool providing detailed anatomic information in the living. It allowed measurement of the high variability of morphology of the quadrigeminal cistern. We defined the lateral landmarks and identified the lateral limit of the cistern. We classified the different shapes of the quadrigeminal cistern as open or closed cisterns. This can be helpful in the choice of the surgical approach to the lesions arising in this area.