A computerized tomography scan (CT or CAT scan) creates cross-sectional images of the body using computers and rotating X-ray devices. Images formed by CT scans contain more information than standard X-ray images. They can display the soft tissues, blood arteries, and bones of the body in different locations. CT scan is used to diagnose diseases and evaluate injuries. Before lumbar puncture, the doctor may recommend a CT scan just to make sure that the patient is stable and a lumbar puncture could be performed on him. A brain CT is performed before lumbar puncture in patients with suspected meningitis including the following: • Adult patients over the age of 60 • Immunocompromised patients • Patients who have been diagnosed with a CNS lesion • Patients who have experienced a seizure during the last week • Patients with an abnormal consciousness level • Patients with focal findings on neurologic examination • Patients with papilledema seen on physical examination, with clinical suspicion of an elevated ICP