Attenuation values of the intracranial arterial and venous vessels by bolus injection of various contrast agents: a study with a single-detector helical CT scanner.

Purpose: We evaluated the arteriovenous contrast on the source images of intracranial three-dimensional computed tomography (CT) angiography (3D-CTA) using a high-concentration (370 mg I/ml) contrast agent in comparison with intermediate-concentration (300 mg I/ml) contrast.

Materials And Methods: With a fixed intravenous injection rate and scanning delay, 3D-CTA was performed using a single-detector helical CT scanner in 30 consecutive patients. We used 100 ml of iohexol 300 for 10 patients, 100 ml of iopamidol 300 for 10 patients, and 80 ml of iopamidol 370 for 10 patients. Attenuation values of the bilateral internal carotid arteries, bilateral middle cerebral arteries, basilar artery trunk, bilateral cavernous sinuses, bilateral basal veins, and Galenic vein were measured quantitatively on the axial CT angiographic source images.

Results: High-concentration contrast significantly increased the attenuation values of the intracranial arterial system without increasing the attenuation of the venous system.

Conclusion: High-concentration contrast is helpful for obtaining valuable arteriovenous contrast on source images with intracranial 3D-CTA.