Cranial computed tomography in subarachnoid hemorrhage: relationship between blood detected by CT and lumbar puncture

We compared the results of cranial computed tomography (CT) and lumbar puncture (LP) in patients who had subarachnoid hemorrhage due to proven ruptured intracranial aneurysm. We found no correlation between the number of red blood cells in the cerebrospinal fluid collected by LP and the amount and extent of blood detected by CT.