Reduced Dose with Maintained Image Quality Utilizing 100 kVp Carotid CT Angiography

摘要

The purpose of this study is to prospectively compare image quality and radiation dose using 100- and 120-kVp techniques for carotid CT angiography. Forty consecutive patients were alternated between the 100 kVp group and 120 kVp group while all other scanning parameters were kept constant. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated for locations along the carotid artery, vertebral artery and circle of Willis. Three radiologists independently assessed subjective image quality including confidence of visualization using a five-point scale. Effective dose was calculated using the dose length product (DLP). CNR and SNR were either similar or better when using 100 kVp for all vessels. Subjective image quality was similar between techniques. Mean effective dose was 36% lower for the 100 kVp than the 120 kVp technique. This study demonstrated that using 100 kVp technique provides 36% dose reduction with significantly higher objective image quality and nonsignificantly higher subjective image quality compared to the 120 kVp technique.