膝关节水平test bolus技术在低电压，大螺距128层双源CT下肢动脉成像中的应用研究

发布时间：2018-05-11 06:03

本文选题：test + bolus　；参考：《南京医科大学》2016年博士论文

【摘要】：目的：评价膝关节水平小剂量测试团注法(test bolus)在低电压,大螺距双源CT下肢动脉成像中的应用价值；对照标准螺距CTA,评价大螺距下肢动脉CTA的图像质量和辐射剂量：对照DSA,分析低电压,大螺距双源CTA对下肢动脉硬化闭塞症诊断的诊断效能。方法：60例怀疑下肢动脉病变的患者分为两组：A组,30例患者,扫描方式为80kVp,大螺距(3.2),采用迭代重建(sinogram-affirmed iterative reconstruction SAFIRE)后处理图像。B组,30例患者,120kVp,标准螺距(1.0),采用滤过反投影法重建(filtered back projection FBP)。A组患者采用膝关节水平小剂量test bolus技术决定扫描延迟时间,B组采用腹主动脉分叉上方团注示踪法(bolus tracking)决定扫描延迟时间。对比剂注射方案A组为,80ml对比剂,速率3ml/s。B组为100ml对比剂,速率为3ml/s。比较两组的平均CT值,信噪比(signal-to-noise ratio SNR),对比信噪比(contrast-to-noise ratioCNR),图像质量评分和辐射剂量。以DSA为金标准,比较两组CTA诊断血管狭窄度的灵敏度,特异度,阳性预测价值,阴性预测价值和准确率结果：A组主动脉分叉(aortic bifurcation AA),双侧股动脉(bilateral common femoral arteries CFA),双侧股浅动脉中段(bilateral mid-superficial femoral arteries SFA),双侧小腿中部(bilateral midealf CA)及平均CT值分别为554.03±83.08HU,569.23±74.95 HU,512.83±97.08 HU,395.95±54.63 HU,507.78±103.01HU,B组的AA,CFA,SFA,CA水平以及平均CT值分别为345.33±86.91 HU,320.55±66.52 HU,328.72±61.78 HU289.52±65.05 HU,317.54±62.03HU,A组的所有CT值均较B组高,且均具有统计学差异(所有PO.001)。B组的平均图像噪声较A组低(A组：11.24±3.79HU,B组：9.33±3.79HU,P0.001)。A,B两组平均SNR分别为51.04±20.29,34.66±9.94,有统计学差异(P0.001),平均CNR分别为44.83±1 7.93,28.26±9.60,有统计学差异(P0.001)。两组图像质量评分无统计学差异(P0.05)。两组有效辐射剂量存在统计学差异(A组：0.76±0.06mSv,B组：4.29±0.63mSv,P0.001)。A组30例患者膝关节水平test bolus技术共获得60条时问密度曲线,其中1例患者一侧胭动脉闭塞,该侧时间密度曲线来源于侧枝循环,30例患者半均峰值时间为28秒。对照DSA比较狭窄度,A组的灵敏度,特异度,阳性预测价值,阴性预测价值和准确率分别为99%,92%,92%,99%,95%,B组的灵敏度,特异度,阳性预测价值,阴性预测价值和准确率分别为98%,93%,93%,99%,96%),两组间各值比较均没有统计学差异(p0.05)。结论：低千伏,大螺距双源CT下肢动脉成像可以大幅降低辐射剂量,同时对于下肢动脉硬化闭塞症具有良好的诊断准确性。采用膝关节水平test bolus技术来决定扫描延迟时间能够有效保证低千伏,大螺距双源CT下肢动脉成像获得满足诊断用图像。
[Abstract]:Objective: to evaluate the value of low dose test bolus in low voltage, large pitch CT arterial imaging of lower extremity. To evaluate the image quality and radiation dose of large pitch lower extremity artery CTA, and to analyze the diagnostic efficacy of low voltage and large pitch dual source CTA in diagnosis of lower extremity arteriosclerosis obliteration. Methods Sixty patients with suspected arterial lesions of lower extremity were divided into two groups: group A (n = 30) and group A (n = 30). The scanning mode was 80kVpwith large pitch of 3.2kVp.Thirty patients in group B underwent iterative reconstruction of sinogram-affirmed iterative reconstruction SAFIRE) images (120kVp) with standard pitch of 1.0kVp.The patients in filtered back projection FBP).A group were reconstructed with filtered back projection FBP).A by using low-dose test bolus technique at knee joint level. The scan delay time was determined by bolus trackingmethod over the abdominal aorta bifurcation in group B. Contrast group A was 80 ml contrast agent, and 3ml/s.B group was 100ml contrast agent at a rate of 3 ml / s. The mean CT value, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), image quality score and radiation dose were compared between the two groups. Using DSA as gold standard, the sensitivity, specificity and positive predictive value of CTA in the diagnosis of vascular stenosis were compared. Results negative predictive value and accuracy results of aortic bifurcation, bilateral common femoral arteries, bilateral mid-superficial femoral arteries of bilateral superficial femoral artery and bilateral midealf CAA of bilateral superficial femoral artery in group A were 554.03 卤83.08HU569.23 卤74.95 HUA 512.83 卤97.08 HU395.95 卤54.63 HUA 507.78 卤103.01HUA, respectively. The average CT values of AACA-CFAA were 554.03 卤83.08HUA, 512.83 卤97.08 HUA, 507.78 卤103.01HUA, the average CT values were 554.03 卤83.08HUA, 512.83 卤97.08 HUA, 395.95 卤54.63 HUA, 507.78 卤103.01HUA, respectively. The CT values of HUA group were 320.55 卤66.52 HUU 328.72 卤61.78 HU289.52 卤65.05 HUA 317.54 卤62.03HUA were higher than that of B group. The average image noise of all PO.001).B group was lower than that of A group (P < 11.24 卤3.79 HUB group: 9.33 卤3.79 HUA = 9.33 卤3.79 HUA, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P 0.001, P < 0.05). There was no statistical difference in image quality score between the two groups (P 0.05). There was statistical difference in effective radiation dose between the two groups. Group A: 0.76 卤0.06mSvnb, group B: 4.29 卤0.63mSvCv. Group A, 30 patients with knee joint horizontal test bolus technique obtained 60 time-asked density curves, including one patient with unilateral popliteal artery occlusion, 1 patient with popliteal artery occlusion. The lateral time density curve was derived from 30 patients with collateral circulation. The half average peak time was 28 seconds. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of DSA in group A were the sensitivity, specificity and positive predictive value of group B, respectively. The negative predictive value and accuracy rate were 98 / 93 and 993 / 995, respectively. There was no statistical difference between the two groups (p 0.05). Conclusion: lower extremity arteriography with large pitch and low voltage can significantly reduce the radiation dose and has good diagnostic accuracy for arteriosclerosis obliterans of lower extremity. Using the horizontal test bolus technique of knee joint to determine the scanning delay time can effectively guarantee the low kilovolt large pitch dual-source CT lower extremity arterial imaging to obtain the satisfied diagnostic image.
【学位授予单位】：南京医科大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R816.2;R543.5

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