| 杨尚文,邵明冉,杨献峰,胡安宁,王钟,蒋辉,朱斌,张冰,辛小燕.“三低”技术联合全模型迭代重建算法在头颈部CT血管成像中的可行性研究[J].中华放射医学与防护杂志,2017,37(1):62-67 |
| “三低”技术联合全模型迭代重建算法在头颈部CT血管成像中的可行性研究 |
| A feasibility study on “Tri-Low” technology in combination with iterative model reconstruction(IMR) algorithm in CT angiography(CTA) of the head-and-neck vessels |
| 投稿时间：2016-08-04 |
| DOI：10.3760/cma.j.issn.0254-5098.2017.01.012 |
| 中文关键词: 血管成像 体层摄影术,X射线计算机 辐射剂量 迭代重建 |
| 英文关键词:Angiography Tomography, X-ray computed Radiation dose Iterative reconstruction |
| 基金项目:江苏省卫生厅青年科研课题（Q201410） |
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| 摘要点击次数: 3435 |
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| 中文摘要: |
| 目的探讨80 kV低管电压、低对比剂注射速率和低对比剂用量的“三低”技术，联合全模型迭代重建（IMR）算法在头颈部CT血管成像（CTA）检查的可行性。方法前瞻性连续收集2015年7-11月行头颈部CTA检查的患者60例，采用随机数字表法将其分为A、B两组，每组各30例。A组为常规剂量组，管电压120 kV，滤过反投影（FBP）重建，对比剂注射速率4.5~5.5 ml/s，注射时间10 s；B组为80 kV低管电压组，分别使用FBP和IMR进行图像重建，得到B1和B2两组图像，对比剂注射速率3.5~4.0 ml/s，注射时间10 s。测量并计算A组、B1组、B2组的图像动脉血管CT值、图像噪声、信噪比（SNR）和对比噪声比（CNR），并由2名放射诊断医师对图像质量按照5分法进行评价。3组图像间动脉血管CT值、图像噪声、SNR和CNR采用单因素方差分析，图像质量主观评价采用Kruskal-Wallis检验，两组检查的容积CT剂量指数（CTDIvol）和剂量长度乘积（DLP）比较采用两个独立样本t检验。结果 A、B1和B2组3组图像质量主观评分范围分别为3~5分、2~4分和3~5分，B1组有12例患者图像之间评分≤2分，图像无法诊断。A和B1、A和B2、B1和B2图像之间评分差异均有统计学意义（t=4.55、-6.58、-2.03，P<0.05）。B2组与A组的图像客观指标SNR和CNR比较差异无统计学意义（P>0.05），但B2和A组图像的SNR、CNR均优于B1组，差异均有统计学意义（t=-12.14、13.39、-9.96、9.45，P<0.05）。B组CTDIvol[（1.7±0.2）mGy]比A组[（8.9±1.0）mGy]减少了80.9%，DLP[（77.9±9.0）mGy·cm]比A组[（415.5±56.7）mGy·cm]减少了81.3%，B组对比剂注射速率[（3.9±0.1）ml/s]比A组[（5.0±0.2）ml/s]减少了22.0%，B组对比剂总量[（39.2±1.9）ml]比A组[（50.3±2.2）ml]减少22.1%，差异有统计学意义（t=39.1、32.2、20.8、20.8，P<0.05）。结论使用80 kV管电压、低对比剂注射速率和用量，并使用IMR算法进行图像重建，进行头颈部CTA扫描是可行的。可以在保证图像质量的基础上，使患者辐射剂量减少81.3%。临床试验注册号中国临床试验注册中心，ChiCTR-BOC-16010060。 |
| 英文摘要: |
| Objective To evaluate the feasibility of low-tube-voltage,low injection rate,low contrast agent dosage in combination with iterative model reconstruction(IMR) algorithm in CT angiography(CTA) of the head-and-neck vessels.Methods Sixty patients who underwent CT angiography of the head-and-neck vessels were randomly divided into groups A and B with 30 cases in each group. Patients in group A received a conventional scan with 120 kVp and filterback projected(FBP) reconstruction. Patients in group B received a low-dose scan with 80 kVp, and image reconstruction with FBP(group B1) and IMR(group B2) algorithm. The contrast agent protocol were as follows:the injection time in all patients was 10s, the injection rate was 4.5-5.5 ml/s in group A while 3.5-4.0 ml/s in group B. The CT values of artery, image noise, signal to noise ratio(SNR) and contrast to noise ratio(CNR) were measured and compared among three groups with One-way ANOVA analysis. Image quality was evaluated by two radiologists with five scale method, and compared with Kruskal-Wallis test. The CT dose index volume (CTDIvol) and dose length product (DLP) were recorded and compared between groups with two independent samples t-test. Results The image quality scores of groups A, B1and B2 were 3-5, 2-4 and 3-5, respectively.Image quality of twelve patients in group B1 couldn't meet the diagnostic requirements but none in group A and B2.The objective image parameters SNR and CNR for group B2 were equal to group A(P>0.05), while those for group B1 were lower than group A(t=13.39, 9.45,P<0.05) and group B2(t=-12.14, -9.96, P<0.05). CTDIvol and DLP for group B were separately 80.9%, 81.3% lower than those of group A(t=39.1, 32.2, P<0.05). The injection rate and contrast agent volume for group B were separately 22.0%, 22.1% lower than those of group A(t=20.8, 20.8, P<0.01).Conclusions It is feasible in CT angiography of the head-and-neck vessels with lower tube-voltage, lower injection rate, lower contrast agent dose and combining with iterative model reconstruction algorithm. This protocol can reduce the radiation dose by 81.3% while maintaining image quality.Trial registration Chinese clinical trial registry,ChiCTR-BOC-16010060. |
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