Computed tomography angiography of the carotid arteries at low kV settings: a prospective randomised trial assessing radiation dose and diagnostic confidence
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Dietrich Beitzke & Florian Wolf & Gundula Edelhauser & Christina Plank & Rüdiger Schernthaner & Michael Weber & Richard Nolz & Johannes Lammer & Ch
- چاپ و سال / کشور: 2011
Description
Objective To assess radiation dose and diagnostic image quality of a low-dose (80 kV) versus a standard-dose (120 kV) protocol for computed tomography angiography (CTA) of the supra-aortic arteries. Methods 64-slice CTA of the supra-aortic arteries was performed in 42 consecutive patients using randomly either 80 or 120 kVat 300 absolute mAs. Intravascular attenuation values, contrast-to-noise (CNR) and signal-to-noise ratio (SNR) measurements were performed at three levels. Two readers assessed image quality by using a four-point scale. The effective dose (ED) was calculated to assess the differences in radiation exposure. Results Intravascular attenuation values at 80 kV were higher in the common carotid artery, the carotid bifurcation and the internal carotid artery (p<0.001). CNR and SNR differed at the internal carotid artery, with higher values in the 80-kV group (p>0.05). Both readers revealed a significantly better image quality at 120 kVonly at the common carotid artery (p <0.001; p=0.007). Mean ED was significantly lower at 80- kV (1.23±0.09 vs. 3.99±0.33 mSv; p<0.001). Conclusion Tube voltage reduction to 80 kV in CTA of the supra-aortic arteries allows for significant radiation dose reduction but has limitations at the level of the common carotid artery.
Eur Radiol DOI 10.1007/s00330-011-2188-1 Received: 9 January 2011 / Revised: 8 April 2011 / Accepted: 15 May 2011
