Bacterial meningitis in neonates and infants - the sonographic picture.

Bacterial meningitis is a major diagnostic and therapeutic problem among children and neonates, with severe, rapidly progressing course and potentially life-threatening complications. Early antibacterial treatment is essential for the patient's favorable prognosis. Cerebral imaging plays an important role in the diagnostic process alongside physical examination and laboratory tests. Magnetic resonance imaging is the gold standard for diagnosing bacterial meningitis. Because of limited availability of magnetic resonance imaging, cranial ultrasound is the first imaging procedure to be performed (if the anterior fontanelle is preserved providing an adequate acoustic window). The safety and reliability of ultrasound examination, possibility to perform the examination at bedside without the need for sedation make cranial ultrasound a useful tool both for preliminary diagnostic investigation and for the monitoring of both treatment and long-term complications. Sonographic findings in patients with bacterial meningitis and possible complications are diverse. Changes can be seen on the surface of the brain, in the extra-axial space, in the ventricular system and in brain tissue. In some cases they can also be visible in the lumbosacral segment of the spinal cord. This paper presents ultrasound characteristics of lesions associated with bacterial meningitis in neonates and infants, based on the authors' own material and data from the available literature.