基于GSI的低剂量对比剂肺动脉成像在肺动脉栓塞诊断中的价值

Clinical Value on Diagnosis of Pulmonary Embolism by Computed Tomography Pulmonary Angiography with Low Dose Contrast Medium Based on GSI

目的:探讨宝石能谱CT(GSI)低剂量对比剂肺动脉成像(CTPA)在肺动脉栓塞(PE)诊断中的价值。方法:选取2016年1月-2017年10月在本院临床拟诊PE需行CTPA检查的患者60例,按照随机数字表法将患者分为A组和B组,每组30例。两组均采用GE Discovery CT 750 HD行CTPA检查,A组采用常规扫描模式,注射对比剂80 m L;B组采用GSI扫描模式,注射对比剂40 m L及0.9%氯化钠溶液40 m L。比较两组的图像质量客观评分、图像质量主观评分、肺动静脉CT差值、诊断阳性率,以及辐射剂量参数、最佳单能量情况。结果:经CTPA检查,A组阳性率为30.0%,与B组的26.7%比较,差异无统计学意义(P>0.05)。B组肺动脉的最佳单能量图像能量水平主要集中于60~70 keV。B组CTDI vol高于A组(P<0.05),A、B组间其他图像质量客观评价指标、图像质量主观评分及辐射剂量参数比较,差异均无统计学意义(P>0.05)。B组肺动脉与同水平静脉的CT差平均值均高于A组(P<0.05)。结论:基于GSI的低剂量对比剂CTPA检查可以获得满意的肺动脉图像,肺动脉各级分支显影良好,对于PE定位及范围判断符合临床诊断的要求,减少了对比剂的用量,具有较高的临床应用价值。

Objective：To explore the value on diagnosis of pulmonary embolism（PE） by computed tomography pulmonary angiography（CTPA） with low dose contrast medium based on gemstone spectral imaging（GSI）.Method：From January 2016 to October 2017,60 patients with clinically diagnosed PE and undergoing CTPA were selected,the patients were randomly divided into group A and group B,according to random digital table method,30 cases in each group.All patients were examined by CTPA using GE Discovery CT 750 HD,and group A was received conventional contrast mode with 80 m L of contrast medium,yet group B was received GSI contrast mode with 40 m L of contrast medium and 40 m L of 0.9% Sodium Chloride Solution.The objective score and subjective score of image quality,the difference value of pulmonary arteriovenous CT,the positive rate of diagnosis,the radiation dose parameters and the best single energy condition between the two groups were compared.Result：By CTPA test,the positive rate of group A was 30.0%,compared with 26.7% of group B,there was no significant difference（P〈0.05）.The optimal single-energy image energy level of pulmonary artery in group B mainly focused on 60-70 keV.The CTDI vol in group B was higher than that in group A（P〈0.05）,there were no significant differences on objective evaluation indexes,subjective evaluation indexes of image quality and radiation dose between group A and group B（P〉0.05）.The mean CT difference between the pulmonary artery and the same vein in group B was higher than that in group A（P〈0.05）.Conclusion：The low dose contrast agent CTPA based on GSI can obtain satisfactory pulmonary artery images,the pulmonary artery branches are well developed,the location and range of PE can meet the requirements of clinical diagnosis,and the dosage of contrast agent is reduced,it has high clinical application value.