Central nervous system disorders

III./3.2.: Magnetic resonance imaging – MR 

MR is the recommended imaging method in meningitis, because it is the most sensitive imaging method for its detection nowadays. On one hand, MR demonstrates the inflammatory changes of meninges very correctly, it is outstanding in the imaging of leptomeningeal contrast enhancement. On the other hand, MR transcends CT by far in the detection of complations developed due to meningitis, although possibly nothing can be observed on the unenhanced T1 weighted images apart from the subarachnoid „filling”. MR images sinusitis and mastoiditis as well which can be accountable for the reason of meningitis. Mucosal thickening: high signal on T2, possibly fluid.

Contrast enhanced MR examination is an excellent imaging method to investigate meningitis (enhancement pattern corresponds to that of CT, however, MR is much more vigorous and demonstrative). Hyperintensive plaques on T2 weighting enhance the contrast on T1 weighted images with contrast (Gd) administration.

Role of MR in demonstration of the complications is very important.

Such as:

• 1) cerebritis,

• 2) ventriculitis (ependymitis),

• 3) further on cerebral atrophy.

• 4) Cerebral infarctions might develop due to vasculitis and phlebitis based thromboses. If the infarction eventuates and cerebral edema is also present, prognosis can be either fatal.

• 5) Principally in children subdural effusions can develop which can be either sterile initially.

• 6) Hydrocephalus might develop if the purulent inflammatory cell debris obstructs the foramen of Monroi, the cerebral aqueduct Sylvii or the outflow of the fourth ventricle (foramen of Luschka).

• 7) Ventricular dilation, widening of the subarachnoid spaces eventuates, and subdural fluid collections can develop.

• 8) Possibly pachymeningitis can be suspected in case of dural enhancement.