Paediatric- Meningitis / Encephalitis

Paediatric- Meningitis / EncephalitisCreated OnMay 7, 2020Last Updated OnOctober 26, 2020byadmin You are here: Main Radiology Paediatric- Meningitis / Encephalitis < All Topics Table of Contents Imaging Indications for imaging before LP in children with suspected bacterial meningitis include: Coma The presence of a cerebrospinal fluid (CSF) shunt History of hydrocephalus Recent history of CNS trauma or neurosurgery Papilledema Focal neurologic deficit (with the exception of palsy of cranial nerve VI [abducens nerve] or VII [facial nerve]) CT Brain The most important role of CT Brain in patients with meningitis is to identify contraindications to lumbar puncture (LP) and complications that require prompt neurosurgical intervention, such as symptomatic hydrocephalus, subdural empyema, and cerebral abscess. Contrast-enhanced CT scans may also help in detecting complications such as venous thrombosis, infarction, and ventriculitis. Ventriculitis is a complication of bacterial meningitis that is seen commonly in neonates. Ependymal enhancement can be seen on contrast-enhanced CT scans. Normal results on CT imaging do not exclude the presence of acute meningitis. Obstructive hydrocephalus can occur with chronic inflammatory changes in the subarachnoid space or in cases of ventricular obstruction. A small, ring-enhanced, hypoattenuating mass (recurrence of abscess) in the left basal ganglia and a left lentiform-shaped subdural fluid collection with enhanced meninges (arrowhead). Acute bacterial meningitis. This axial nonenhanced CT Scan shows mild ventriculomegaly and sulcal effacement. This contrast-enhanced axial CT scan shows left-sided parenchymal hypoattenuation in the middle cerebral artery territory, with marked herniation and a prominent subdural empyema. This axial computed tomography scan shows bilateral subdural effusion (empyema) and parenchymal low-attenuating areas. Magnetic Resonance Imaging Most sensitive modality for the diagnosis of bacterial meningitis It helps to detect the presence and extent of inflammatory changes in the meninges as well as complications. However meningeal enhancement is nonspecific, can be also caused by neoplasm, hemorrhage, sarcoidosis, and other noninfectious inflammatory disorders. Non-contrast MRIs of patients with uncomplicated acute bacterial meningitis may demonstrate obliterated cisterns and the distention of the subarachnoid space with widening of the interhemispheric fissure, which is reported to be an early finding in severe meningitis or may be unremarkable. T2-weighted images are sensitive to abnormal tissue water distribution and, thus, may show cortical hyperintensities that are reversible and believed to represent edema. Diffuse enhancement of the subarachnoid space is characteristic. Acute bacterial...

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