Clinical value of energy spectrum scanning combining with monitoring on popliteal artery level in dual low dose CT angiography for lower extremity arteries
Clinical value of energy spectrum scanning combining with monitoring on popliteal artery level in dual low dose CT angiography for lower extremity arteries
目的:探讨能谱扫描结合胭动脉水平监测在双低剂量(低辐射剂量和低对比剂剂量)下肢动脉血管CT成像(CTA)中的应用价值.方法:前瞻性纳入需行下肢CTA检查的111例患者,分为A、B、C三组.A组(35例)采用常规扫描模式,对比剂105 mL,监测腹主动脉;B组(38例)采用能谱扫描模式,对比剂95 mL,监测腹主动脉;C组(38例)采用能谱扫描模式,对比剂85 mL,监测胭动脉.记录3组的辐射剂量与对比剂剂量.对于B、C两组,生成50 keV单能图像进行分析.由2位医师采用5分法对3组图像腹髂段(AIS)、股胭段(FPS)和膝下段(LKS)进行图像质量评分.测量CT值及噪声值,计算信噪比(SNR)及对比噪声比(CNR).比较3组图像间的客观参数、主观评分、辐射剂量和对比剂剂量.结果:C组对比剂剂量较A组降低了 19.04％,ED降低了 14％,差异均有统计学意义(P均＜0.05).B、C两组在各血管处CT值均高于A组(P＜0.05).从腹主动脉到踝动脉,C组的客观图像质量优势逐渐显现,在踝动脉处的SNR和CNR最高,其次为B组,A组最低,差异均有统计学意义(P均＜0.05).图像质量主观评分方面,AIS段3组图像质量评分差异无统计学意义;FPS段B、C组评分高于A组;LKS段C组评分最高,B组次之,A组最低,差异有统计学意义(P＜0.05).结论:与传统下肢C T A、腹主动脉点监测扫描方案相比,能谱结合胭动脉水平监测点扫描方案在双低剂量下可提高下肢动脉的图像质量,尤其提高了对膝下血管的显示能力,具有较高的临床应用价值.
Abstract
Objective:To explore the clinical value of energy spectrum scanning combining with monitoring on popliteal artery level in dual low(low radiation dose and low contrast dose)CT angiog-raphy(CTA)for lower extremity arteries.Methods:One hundred and eleven patients requiring lower limb CTA were prospectively divided into three groups:Group A(35 cases):conventional scanning,105mL of contrast,monitoring on abdominal aorta;Group B(38 cases):gem spectral imaging(GSI),95mL of contrast,monitoring on abdominal aorta;Group C(38 cases):GSI,85mL of contras,monito-ring on popliteal artery.For Groups B and C,50keV single energy images were generated for analysis.Subjective scoring was performed by two physicians independently on the abdominal iliac segment(AIS),femoral popliteal segment(FPS),and lower knee segment(LKS)using 5-point scale.The CT values and noise(SD)values of the regions of interest(ROIs)were measured.The signal-to-noise rati-o(SNR)and contrast-to-noise ratio(CNR)were then calculated.Objective parameters,subjective scores,and doses among three-group images were compared.Results:Compared to Group A,the con-trast dose for Group C decreased in 19.04％;the effective dose decreased in 14％(P＜0.05).Regarding CT values,the CT values of Group B and Group C images were higher than those of Group A on all vessels(all P＜0.05).The objective parameters of Group C images gradually stood out from the ab-dominal aorta to the ankle artery.There was highest SNR in Group C on the ankle artery,followed by Group B,and Group A,all P＜0.05.Regarding subjective scores,there was no statistical difference in the AIS segment among the three groups,while Group B and Group C showed higher scores than Group A in the FPS segment.For the LKS segment,Group C images had the highest score,followed by Group B,and the lowest score in Group A,with a statistical difference.Conclusion:Compared to con-ventional lower extremities CTA with monitoring on the abdominal aorta,the developed method com-bining GSI scanning and monitoring on the popliteal artery can provide better image contrast and im-prove the display of LKS arteries at dual low dose level.
关键词
能谱CT/体层摄影术,X线计算机/下肢动脉/辐射剂量/对比剂剂量/阈值监测
Key words
Energy spectrum CT/Tomography,X-ray computed/Lower limb arteries/Radia-tion dose/Contrast agent dose/Threshold monitoring
维普
万方数据