The mamillopontine distance is measured on midsagittal T1WI MRI from the anterior root of the mammillary body to the top of the pons parallel to the anterior mesencephalon or the shortest distance between the center of the mammillary bodies and the upper surface of the pons.
In normal subjects, it should be >5.5 mm 1.
It is decreased in conditions that either depress the floor of the third ventricle or change the position of the brain within the intracranial cavity. Such conditions include:
- 1. Shah LM, McLean LA, Heilbrun ME et-al. Intracranial hypotension: improved MRI detection with diagnostic intracranial angles. AJR Am J Roentgenol. 2013;200 (2): 400-7. doi:10.2214/AJR.12.8611 - Pubmed citation
- 2. Segev Y, Metser U, Beni-Adani L et-al. Morphometric study of the midsagittal MR imaging plane in cases of hydrocephalus and atrophy and in normal brains. AJNR Am J Neuroradiol. 2001;22 (9): 1674-9. AJNR Am J Neuroradiol (full text) - Pubmed citation