Neuroanatomy Atlas in Clinical Context

MENINGITIS 63

A

B

Position of tentorium cerebelli

Position of tentorium cerebelli

S

SSS

Falx cerebri

TS

D

C

Falx cerebri

Superior sagittal sinus

Falx cerebri

Superior sagittal sinus

is also apparent that the meningeal inflammation and the inflamma tion within the SAS are more subtle than lesions such as meningioma, hemorrhage, or brain tumor. While these may enhance in similar ways, such as a mild subarachnoid hemorrhage versus leptomeningitis, each has its unique clinical features and presentation that lead to a cor rect diagnosis. Vessels located within the subarachnoid space may also enhance as they most likely contain infectious material and the organ isms may infiltrate the vessel walls. As noted in Figure 4-2, the inflam mation may also extend to involve the dura mater ( pachymeningitis ). The more common causative agents for meningitis, and the age groups with which they are more frequently associated, are discussed earlier in this chapter. Copyright © Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. 2024

4-3 Examples of meningitis ( pachymeningitis ) that extensively involves both sides of the central nervous system ( A – D , all axial) in the adult. In A and B , note the enhancement of the meninges over the temporal lobe (arrows), at the location of the tentorium cerebelli, and of the venous sinuses (SSS, superior sagittal; S, sigmoid; TS, transverse). At different axial levels, enhancement is clearly visible on the brain surface ( B , C , arrows), along the dural reflections (tentorium cerebelli and falx cerebri, B – D ), and within the sulci ( C ). In addition, enhancements over the curvature of the hemisphere ( D ) are suggestive of focal collections of inflammation largely sequestered in the leptomeninges . As seen in these samples, meningitis can be imaged using gadolinium and to a reasonable level its degree and extent visualized. However, it