低对比剂摄入量能谱肺动脉成像虚拟平扫代替胸部平扫的可行性  

Feasibility of Utilizing Virtual Non-Contrast Images Derived from Spectral CT for Pulmonary Angiography with Low Contrast Medium Intake to Replace True Non-Contrast Images of Chest

作　　者：方鑫[1] 刘义军[1] 王旭[1] 李贝贝 姜健 张竞颐 FANG Xin;LIU Yijun;WANG Xu;LI Beibei;JIANG Jian;ZHANG Jingyi(Department of Radiology,the First Affiliated Hospital of Dalian Medical University,Dalian 116011 China)

机构地区：[1]大连医科大学附属第一医院放射科,辽宁大连116011

出　　处：《中国医学影像学杂志》2024年第9期956-960,共5页Chinese Journal of Medical Imaging

摘　　要：目的 探讨能谱CT虚拟平扫技术在肺动脉成像(CTPA)中代替胸部平扫降低患者辐射剂量的可行性。资料与方法 前瞻性收集2022年2—11月于大连医科大学附属第一医院行CTPA检查的56例患者,均接受常规胸部平扫及能谱CTPA增强扫描。分别测量胸部平扫和虚拟平扫图像上胸主动脉、肺动脉主干、竖脊肌及肺尖层面、气管隆嵴层面、肺底层面的肺实质CT值及噪声,并计算胸主动脉、肺动脉信噪比、对比噪声比。对两组图像质量及碘残留进行主观评价,并检验主观评分的一致性。记录患者剂量长度乘积、CT容积剂量指数及对比剂用量。比较胸部平扫和虚拟平扫图像各感兴趣区CT值、信噪比、对比噪声比、辐射剂量和主观评分。结果 2名医师的主观评分一致性较好(Kappa=0.984~0.992,P<0.05),胸部平扫、虚拟平扫图像主观评分分别为(4.75±0.65)分、(4.65±0.49)分,差异无统计学意义(t=0.630,P=0.437)。胸部平扫与虚拟平扫图像胸主动脉、肺动脉、各区域肺组织CT值差异无统计学意义(P>0.05);肺动脉及胸主动脉信噪比、对比噪声比差异无统计学意义(P>0.05)。用CTPA的虚拟平扫代替常规胸部平扫,患者辐射剂量由(7.27±1.74)mSv减少至(3.26±0.84)mSv,减少约55%。结论 CTPA虚拟平扫可代替胸部常规CT平扫用于肺部疾病筛查,大幅降低患者的辐射剂量。Purpose To explore the feasibility of using virtual non-contrast images derived from spectral CT for pulmonary angiography(CTPA) to replace true non-contrast scan of chest, in order to reduce radiation dose. Materials and Methods Fifty-six patients undergoing CTPA examination in the First Affiliated Hospital of Dalian Medical University were prospectively enrolled. All patients underwent both conventional chest CT and spectral CTPA scan. On both virtual unenhanced images and true unenhanced images,CT values and standard deviation values of the pulmonary parenchyma in the level of thoracic aorta, main pulmonary artery, erector spine,as well as pulmonary apex, tracheal carina, and lung base were measured. Signal noise ratio and contrast noise ratio of thoracic aorta and pulmonary artery were calculated. The image quality and iodine residue of the two groups was evaluated. The consistency of subjective scores was also assessed. Dose length product, CT dose index volume and contrast agent dosage were recorded. The CT value, signal noise ratio, contrast noise ratio, radiation dose and subjective score of each region of interest in true unenhanced and virtual unenhanced images were compared. Results The inter-observer subjective scores were consistent(Kappa=0.984-0.992, P<0.05). The subjective scores of the chest true unenhanced and virtual unenhanced images were 4.75±0.65 and 4.65±0.49, respectively, with no statistical difference(t=0.630, P=0.437). There was no significant difference in CT values of thoracic aorta, pulmonary artery and lung tissues between true unenhanced and virtual unenhanced images(P>0.05). There was no significant difference in signal noise ratio and contrast noise ratio between pulmonary artery and thoracic aorta(P>0.05). Replacing conventional chest scan with virtual unenhanced images of CTPA reduced the radiation dose by approximately 55%, reducing from(7.27±1.74) mSv to(3.26±0.84) mSv. Conclusion It is feasible to use CTPA virtual non-contrast images to replace conventional unenhanced CT

关 键 词：肺动脉成像 体层摄影术 X线计算机 造影剂 噪声 信噪比 辐射剂量 胸部 

分 类 号：R445.3[医药卫生—影像医学与核医学] R816.4[医药卫生—诊断学]