卓　娜，马延贺，张　洪（．天津医科大学第二医院超声科，天津　300；．天津市胸科医院影像科，天津　300）



双能CT肺灌注成像在诊断肺栓塞中的价值

卓娜1，马延贺2，张洪2
（1．天津医科大学第二医院超声科，天津300211；2．天津市胸科医院影像科，天津300222）

摘要目的：评价双能CT（DECT）低对比剂肺灌注成像诊断肺动脉栓塞的图像质量及辐射剂量。方法：接受双源CT扫描的肺栓塞疑似患者290例，根据扫描方式不同分为两组：DECT检查组80例；常规检查组210例。分别以主观和客观法评价图像质量：主观评价法由两名影像科诊断医生以5分法评价图像质量；客观评价法采用测量信号噪声比（SNR）和对比度噪声比（CNR）。分别记录、计算两组受检者的辐射剂量。对两名影像科诊断医师的主观评级采用χ2检验。对辐射剂量、SNR和CNR的差异采用t检验。结果：两组患者的年龄、性别差异均无统计学意义。DECT肺灌注成像与常规CTPA成像的图像质量主观评级均在1级以上，两者的诊断效能、图像质量评分差别无统计学意义。两组间在SNR、CNR、辐射剂量均无统计学差异。结论：DECT低对比剂用量肺灌注成像所得的图像能够满足临床诊断需要，降低了受检者对比剂风险。

关键词肺栓塞体层摄影技术；X线计算机血管造影术；双能量肺灌注成像；双源CT

Value of dual energy CT pulmonary perfusion imaging in diagnosis of pulmonary embolism

ZHUO Na1，MA Yan-he2，ZHANG Hong2
（1．Department of Ultrasound，The Second Hospital，Tianjin Medical University，Tianjin 300211，China;2 .Department of Radiology，Tianjin Chest Hospital,Tianjin 300222,China）

Abstract Objective:To compare the radiation dose and image qualities of dual source CT in dual energy scan mode pulmonary perfusion imaging and conventional CT pulmonary artery angiography（CTPA）.Methods:Two hundred and ninety patients with suspected pulmonary embolism,according to the scanning mode,were divided into two groups:80 cases underwent DECT examination;210 cases underwent routine CTPA examination.Image quality was evaluated by 5 points method,and by measuring the signal to noise ratio(SNR)and contrast to noise ratio(CNR).Radiation doses were recorded.The quality score of two groups were obtained by Chi square test.Differences in the radiation dose,SNR and CNR were acquired by t test.Results:Age,gender differences of two groups were not statistically significant.DECT and conventional CTPA acquisition,reconstruction could promote the diagnosis,and the difference showed no statistical significance.There was no significant difference in SNR,CNR and radiation dose between the two groups.Conclusion:Dual energy CT with low dose contrast agent can promote clinical diagnosis,reducing the risk of the contrast agent.

Key words pulmonary embolism;tomography technology；X-ray computed;angiography dual-energy lung perfusion imaging;dualsource

CT肺动脉造影（CT pulmonary angiography，CTPA）能够有效地诊断肺动脉栓塞并且评估肺动脉栓塞的严重程度，在临床中有广泛应用。双源CT （dual-source CT，DSCT）在双能量（dual energy CT，DECT）扫描模式下可实现肺灌注成像的同时，可以重建出近似120 kV管电压的CTPA图像。在显示肺动脉的解剖信息的同时，也能显示肺动脉的血流灌注状态，提高了亚段肺栓塞的检出率，在临床中有巨大的应用价值[1-2]。……