Cerebral CT angiography with iterative reconstruction at 70kVp and 30mL iodinated contrast agent: Initial experience.

<bold>Objectives: </bold>To evaluate the radiation dose and image quality of cerebral CT angiography (CTA) at 70kVp with 30mL iodinated contrast agent.<bold>Methods: </bold>One hundred patients were prospectively classified into two groups: Group A (n=50), 120kVp cerebral CTA with 60mL iodinated contrast agent reconstructed by filtered back projection (FBP) and Group B (n=50), 70kVp with 30mL iodinated contrast agent reconstructed by sinogram-affirmed iterative reconstruction (SAFIRE). CT values, noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the internal carotid artery (ICA) and middle cerebral artery (MCA) were measured. Subjective image quality was evaluated. Effective dose (ED) was calculated.<bold>Results: </bold>The mean CT values of the ICA and MCA of Group B were higher than those of Group A (all P<0.001). The mean noise of Group A was lower than that of Group B (P<0.001). SNRICA, SNRMCA and CNRICA, CNRMCA of Group A were higher than Group B (all P<0.001). There was no difference in vessel sharpness, noise, and overall quality between the two groups (all P>0.05). ED of Group B (0.2±0.0mSv) was lower than Group A (1.3±0.1 mSv) (p<0.001).<bold>Conclusion: </bold>Cerebral CTA with iterative reconstruction at 70kVp and 30mL iodinated contrast agent is feasible, allowing for substantial dose reduction compared with conventional cerebral CTA protocol. [ABSTRACT FROM AUTHOR]