Question: which one of the following is used to remove cerebrospinal fluid for diagnostic purposes?
Answer: A lumbar puncture (LP), also called a spinal tap, is an invasive outpatient procedure used to remove a sample of cerebrospinal fluid (CSF) from the subarachnoid space in the spine. (This test is similar to a blood test, in which a needle is inserted into an artery to collect blood for testing.)