Three-dimensional computed tomographic angiography with low loads of contrast agent in acute subarachnoid hemorrhage

In the pre-operative evaluation of aneurysmal subarachnoid hemorrhage (SAH), three-dimensional computed tomographic angiography (3D-CTA) is very helpful, However, it is usually difficult to perform 3D-CTA following four-vessel cerebral angiography in the setting of acute SAH because of high loads of contrast agent. The present report is designed to enable 3D-CTA following catheter angiography for surgical planning. Fourteen consecutive patients with acute SAH underwent four-vessel cerebral angiography. After identification of the aneurysm, all patients were moved to the CT room next to the angiography room under catheterization. Contrast agent (10 ml) was diluted with 40 ml of heparinized saline. This diluted contrast agent was then injected through intra-arterial catheter for 3D-CTA. 3D-CTA with diluted contrast agent which was injected through intra-arterial catheter revealed sufficiently clear images. in addition, this method could provide anatomical information that was not readily available from catheter angiography. 3D-CTA with additional low dose of contrast agent can immediately follow four-vessel cerebral angiography in the setting of acute SAH. No complications were noted throughout the procedures. It has been our experience that the imaging modality in combination with not only catheter angiography but also 3D-CTA is advantageous in case of acute SAH and provides better detail for surgical planning.