Epidural blood patch illustrated by CT-epidurography.

Four patients, who received epidural blood patch to treat postdural puncture headache, were examined with computed tomography in order to demonstrate the distribution of the injected blood. Blood alone could not be identified, but adding 2 ml contrast agent Iohexol 180 mg J/ml (Omnipaque, Nycomed Imaging) to 18 ml blood gave an excellent demonstration of the distribution of the blood in the epidural space, both cranio-caudally (7-14 segments) and spatially in relation to the epidural septae. The blood-contrast media had a strong affinity to the dural sac. There was no support of the space filling effect of blood patch.