第3代双源CT自动管电压选择技术颞骨扫描在听力障碍儿童患者中的应用

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

目的评估第3代双源CT自动管电压选择技术(CARE kV)行颞骨扫描在听力障碍儿童患者中的应用价值。方法将27例未满18岁患有听力障碍的儿童患者随机分为2组:A组(n=14):采用第2代双源CT和CARE kV及正弦图确定迭代重建技术;B组(n=13):采用第3代双源CT和CARE kV及高级模拟迭代重建技术。扫描范围为眉弓至乳突下缘。测量目标结构CT值及图像噪声,计算信噪比(SNR),对图像质量进行主观盲法评分。结果两组患者各解剖结构间的CT值、图像噪声和SNR差异均无统计学意义(P均>0.05)。两组患者10个解剖结构间的主观评分差异均无统计学意义(P均>0.05)。B组患者的CT容积剂量指数和剂量长度乘积分别为(11.62±1.92)m Gy和(106.92±37.48)m Gy·cm,较A组的(21.28±2.19)m Gy(t=12.15,P<0.001)和(229.65±56.26)m Gy·cm(t=6.62,P<0.001)分别降低了45%和53%。结论与第2代双源CT相比,第3代双源CT CARE kV技术颞骨扫描可在保证图像质量的前提下,明显降低辐射剂量。

Objective To evaluate the radiation dose and image quality of the third-generation dualsource 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 m A） and sinogram-affirmed iterative reconstruction; and Group B（ n = 13）, examined with CARE kV（ reference with 100 kV and 171 m A） 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） m Gy and（ 106. 92 ＋ 37. 48）m Gy·cm,respectively,in group B and（ 21. 28 ＋ 2. 19） m Gy（ t = 12. 15,P〈0. 001） and（229. 65 ＋ 56. 26）m Gy· 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.