Application of Third-generation Dual-source CT for Ultra-high Resolution Temporal Bone Imaging Using Automated Tube Voltage Adaptation in Children with Hearing Impairment.

Objective To evaluate the radiation dose and image quality of the third-generation dual-source CT using automated tube voltage adaptation (CARE kV) in temporal bone scanning in pediatric patients with hearing impairment. Methods Totally 27 children with hearing impairment less than 18 years old were randomly divided into two groups:Group A (n=14),examined with CARE kV (reference with 100 kV and 214 mA)and sinogram-affirmed iterative reconstruction;and Group B (n=13),examined with CARE kV (reference with 100 kV and 171 mA)and advanced modeled iterative reconstruction. The scan range was from eyebrow to the end of the mastoid process. CT values and image noise were measured.The signal to noise ratio (SNR)was calculated. Subjective image quality was assessed by two radiologists and later in a consensus reading. Results There was no significant difference in CT value,image noise,and SNR between these two groups (all P>0.05). Also,the subjective scores of the 10 anatomical structures showed no significant difference (all P>0.05). The CT dose index volume and dose-length product were (11.62+1.92)mGy and (106.92+37.48)mGy·cm,respectively,in group B and (21.28+2.19)mGy (t=12.15,P<0.001)and (229.65+56.26)mGy·cm (t=6.62,P<0.001)in group A,decreased by 45% and 53%. Conclusion Compared with the second-generation dual-source CT,the third-generation dual-source CT for the scanning of temporal bone with CARE kV can ensure image quality and reduce radiation dose.