低剂量容积CT灌注重组全时相CTA对子宫动脉的显示价值

The Value of Deriving High-Quality CT Angiographic from Pelvic Low-Dose CT Perfusion Data in Displaying Uterine Artery

目的探讨基于盆腔CT灌注成像(CTP)数据重组高质量CT血管造影(CTA)图像用于评估子宫动脉的可行性。方法搜集2018年1月至2020年8月行盆腔CTP和盆腔常规CTA(sCTA)检查的50例女性患者,分为A1组[CTP,动态CTA动脉期(dCTAa)重组]、A2组[CTP,全时相最大密度投影CTA(tMIP-CTA)]和B组(sCTA)。分别在腹主动脉根部、两侧髂总动脉、髂外动脉、髂内动脉、子宫动脉起始段选取感兴趣区(ROI),测量各组图像血管CT值和噪声(IN),计算信噪比(SNR)和对比噪声比(CNR),采用5分法对各组双侧子宫动脉进行主观评分。统计分析客观指标及主观评分差异。结果血管CT值、IN、SNR、CNR在A1、A2和B组间均有统计学差异(P<0.05)。血管CT值在A1组和A2组均明显高于B组(P<0.001),A1组和A2组差异无统计学意义(P=0.481)。IN在A1组明显高于A2组和B组(P<0.001),A2组和B组差异无统计学意义(P=0.112)。SNR在A2组高于A1组和B组图像,A1组最低(P<0.05)。CNR在A2组高于A1组(P<0.001),余组间差异无统计学意义(P>0.05)。双侧子宫动脉可诊断率、图像质量主观评分比较A1组、A2组和B组间差别有统计学意义(P<0.001),组间两两比较左侧A2组100%可诊断、右侧A2组96%可诊断,主观评分A2组优于A1组和B组,差异有统计学意义。双侧子宫动脉图像质量评分有较强的一致性(加权Kappa分别为0.63、0.62)。结论基于盆腔CTP数据重组全时相CTA重组图像技术显示子宫动脉良好,可用于盆腔肿瘤起源及供血血管评估。

Objective To explore the feasibility of reconstruction of high quality angiographic images based on pelvic CT perfusion data. Methods A total of 50 female patients who underwent pelvic CT perfusion and routine pelvic CT angiography in Minhang District Central Hospital from January 2018 to August 2020 were retrospectively collected.They were divided into two groups: group A(CT perfusion, 25 cases, 50 ml contrast agent) and group B(conventional CT angiography, 25 cases, 90 ml contrast agent).In group A,dynamic CT angiography(A1 group) and temporal maximum intensity projection CT angiography(A2 group) were obtained by different vascular reconstruction methods.In group B,conventional single-phase CT angiography was obtained by reconstruction.Areas of interest were selected from the abdominal aortic root, the initial segments of bilateral common iliac artery, external iliac artery, internal iliac artery and uterine artery, respectively.CT values and noise(IN) of the vessels IN image groups A1,A2 and B were measured, and the signal-to-noise ratio(SNR) and contrastive noise ratio(CNR) were calculated.Meanwhile, the development of bilateral uterine arteries in group A1,A2 and B was evaluated by two senior physicians using a 5-point method.The non-parametric test method Kruskal Wallis test was used to analyze the data of groups A1,A2 and B.If there were overall differences, the chi-square segmentation was used for pairwise comparison. Results There were statistically significant differences in CT value, IN, SNR and CNR among A1,A2 and B groups(P< 0.05).Vascular CT values in A1 and A2 groups were significantly higher than those in B group(P< 0.001),and there was no statistically significant difference between A1 and A2 groups(P=0.481).In IN group A1 was significantly higher than that IN group A2 and B(P< 0.001),and there was no statistically significant difference between group A2 and B(P=0.112).SNR in group A2 was higher than that in group A1 and B,and the SNR in group A1 was the lowest(P< 0.05).The CNR in the A2 group was higher than that in the A1 group(P< 0.001),and there was no statistically significant difference between the other groups(P> 0.05).Comparison of the diagnostic rate of left uterine artery showed statistically significant difference between group A1,group A2 and group B(P< 0.001).Pairwise comparison between groups showed 100% diagnostic rate in group A2,which showed statistically significant difference compared with group A1 and group B.There was a statistically significant difference in the diagnostic rate of right uterine artery between A1,A2 and B groups(P< 0.001).Pairwise comparison between groups showed that 96% of the right uterine artery could be diagnosed, which was statistically significant different from A1 and B groups.Subjective score of image quality: the difference of bilateral uterine artery image quality score between A1,A2 and B group was statistically significant(P< 0.001);pairwise comparison between A1 group and A2,A2 group and B group showed statistically significant difference(P< 0.001).There was no 1 score of bilateral uterine artery in the subjective score of image quality in Group A1,A2 and B.The results of bilateral uterine artery image quality were consistent between the two physicians(weighted Kappa= 0.63 and 0.62,respectively). Conclusion Temporal maximum intensity projection CT vascular image reconstruction based on pelvic perfusion data has excellent vascular image quality.