基于定位像的自动管电压选择技术与常规固定管电压技术在胰腺实性病变成像中的比较  

Comparison of Topogram-based Automated Selection of Tube Potential and Fixed Tube Potential in Imaging Solid Pancreatic Lesions

作　　者：徐凯[1] 朱亮[1] 薛华丹[1] 李平[1] 孙照勇[1] 杜瑶[1] 王沄[1] 金征宇[1] 

机构地区：[1]中国医学科学院北京协和医学院北京协和医院放射科,北京100730

出　　处：《中国医学科学院学报》2017年第1期88-94,共7页Acta Academiae Medicinae Sinicae

基　　金：国家自然科学基金(81371608);卫生公益性行业科研专项项目(201402001;201402019)~~

摘　　要：目的比较基于定位像的自动管电压选择技术和固定管电压技术在胰腺实性病变成像中的图像质量和辐射剂量。方法回顾性分析2014年1月至2016年8月在北京协和医院就诊经术后病理证实为胰腺实性病变并行术前双源CT检查的113例患者的临床资料,其中,接受固定管电压(120 kV)和管电流可调扫描患者53例(组1),接受管电压(管电压分档:90、100 kV)和管电流自动调节扫描患者60例(组2)。由2名经验丰富的放射科医生共同测量患者腹围,评估动脉期和门脉期图像的主观图像质量评分及客观图像质量参数,并记录扫描的剂量参数。结果组2的60例患者中,有45例接受90 kV扫描,15例接受100 kV扫描;90 kV组患者的平均腹围为(287±24)mm,明显低于100 kV组的(328±22)mm(t=0.731,P=0.0008)。组2的平均CT容积剂量指数为(3.9±1.0)m Gy,较组1的(9.0±1.9)m Gy降低了56.7%(t=17.5,P=0.0003);平均剂量长度乘积为(109±38)m Gy·cm,较组1的(276±83)m Gy·cm降低了60.5%(t=14.0,P=0.0007)。组2动脉期及门脉期图像的背景噪声标准差分别为(6.4±0.9)和(6.4±1.0)HU,均明显高于组1的(5.6±1.4)(t=-3.757,P=0.0003)和(5.5±1.4)HU(t=-3.828,P=0.0006)。组2动脉期的胰腺病灶、腹主动脉和门脉期的胰腺病灶、门静脉主干的信噪比分别为18.8±9.3、76.0±19.3和17.4±6.7、33.1±7.2,均明显高于组1的13.1±8.7(t=-3.379,P=0.001)、56.5±22.6(t=-2.268,P=0.025)和14.1±8.1(t=-2.283,P=0.024)、28.9±8.8(t=-2.613,P=0.009)。结论基于定位像的第3代双源CT自动管电压选择技术应用于胰腺实性病变时,可减低辐射剂量,而图像质量与第2代双源CT固定管电压技术大致相当。Objective To evaluate the image quality and radiation exposure in multidetector computed tomography（ MDCT） with automated topogram-based tube potential selection, compared to fixed tube potential,in patients with solid pancreatic lesions. Methods The preoperative pancreatic dual-source CT images of 113 patients who were confirmed as solid pancreatic lesions by postoperative pathology in the Peking Union Medical College Hospital from January 2014 to August 2016 were retrospectively analyzed. Among them,53 patients were examined on fixed tube potential at 120 kV, and tube current was automatically modulated（ group 1）. Sixty patients underwent topogram-based automatic tube potential selection（ Tube voltage step： 90,100 kV） and automated m A modulation（ group 2）. Two experienced radiologists measured the body sizes, assessed subjective and objective image quality of arterial phase and portal phase, and recorded radiation parameters including CT dose index volume（ CTDIvol） and dose-length product（ DLP）. Results Of 60 patients in group 2,45 patients were scaned at 90 kV,15 patients were scaned at 100 kV. The average body diameter [（ 287 ± 24）mm] in 90 kV group was significantly lower than that [（ 328 ± 22） mm] in 100 kV group（ t = 0. 731, P =0. 0008）. The mean CTDIvol[（3. 9 ± 1. 0） m Gy]in group 2 was significantly lower than in group 1 [（9. 0 ±1. 9） m Gy], reduced by 56. 7 %（ t = 17. 5, P = 0. 0003）. The average DLP [（ 109 ± 38） m Gy · cm] in group 2 was significantly lower than that in group 1 [（ 276 ± 83） m Gy· cm ], reduced by 60. 5 %（ t = 14. 0,P = 0. 0007）. In group 2, the standard deviations of images background noise in arterial and portal phase were（6. 4 ± 0. 9） and（6. 4 ± 1. 0） HU,respectively,which were significantly higher than those in group 1 [（5. 6 ±1. 4） HU, t =- 3. 757, P = 0. 0003;（ 5. 5 ± 1. 4） HU, t =- 3. 828, P = 0. 0006]. In group 2, the signal to noise ratios of pancreatic lesions,abdominal aorta in arterial

关 键 词：第3代双源CT 胰腺实性病变 自动管电压选择技术 固定管电压技术 图像质量 辐射 

分 类 号：R814.42[医药卫生—影像医学与核医学]