PT  - JOURNAL ARTICLE
AU  - Eller, A.
AU  - Wiesmüller, M.
AU  - Wüst, W.
AU  - Heiss, R.
AU  - Kopp, M.
AU  - Saake, M.
AU  - Brand, M.
AU  - Uder, M.
AU  - May, M.M.
TI  - Carotid CTA at the Lowest Tube Voltage (70 kV) in Comparison with Automated Tube Voltage Adaption
AID  - 10.3174/ajnr.A6108
DP  - 2019 Aug 01
TA  - American Journal of Neuroradiology
PG  - 1374--1382
VI  - 40
IP  - 8
4099  - http://www.ajnr.org/content/40/8/1374.short
4100  - http://www.ajnr.org/content/40/8/1374.full
SO  - Am. J. Neuroradiol.2019 Aug 01; 40
AB  - BACKGROUND AND PURPOSE: CTA is the imaging modality of choice in many institutions for the evaluation of the supraaortic vessels, but radiation exposure remains a matter of concern. Our aim was to evaluate a 70-kV protocol for CT angiography of the carotid arteries with respect to image quality and radiation exposure compared with automated tube voltage adaption.MATERIALS AND METHODS: A total of 90 consecutive patients were included in this prospective study and randomized to the study group (n = 45, 70 kV) or control group (n = 45, automated tube voltage adaptation). Volume CT dose indices and dose-length products were recorded in the examination protocol. Image quality was assessed as arterial vessel contrast, signal-to-noise ratio, contrast-to-noise ratio, and contrast-to-noise ratio in reference to the radiation dose. Subjective overall image-quality analysis, image-artifact analysis, and diagnostic evaluation were performed by 2 observers by using a 4-point Likert scale.RESULTS: Radiation exposure was significantly lower in the study group (volume CT dose index reduced by 22%, dose-length product reduction by 20%; each P < .001). Contrast (P = .15), SNR (P = .4), and contrast-to-noise ratio (P = .5) did not show significant differences between the groups. The contrast-to-noise ratio in reference to the radiation dose was not significantly increased using the study protocol (P = .2). Subjective image quality and visualization of pathologic findings did not differ significantly between the groups.CONCLUSIONS: Carotid CTA using the lowest available voltage (70 kV) is feasible at very-low-dose levels, while overall image quality is comparable with protocols using automated tube voltage selection.Arelative attenuationBMIbody mass indexCcontrastCNRcontrast-to-noise ratioCNRDcontrast-to-noise ratio in reference to the radiation doseCTDIvolvolume CT dose indexDLPdose-length product