In case of meningitis, intraventricular sediments showing diffusion restriction on brain magnetic resonance imaging are highly suggestive of pyogenic ventriculitis for which early diagnosis is crucial for appropriate treatment.
Le Fevere De Ten Hove, F., & Reumont, T. (2020). Pyogenic Ventriculitis Caused by Listeria Monocytogenes. Journal of the Belgian Society of Radiology, 104(1), 13. https://doi.org/10.5334/jbsr.2033 (Original work published 2020)