摘要
目的 探讨能谱CT最佳单能量图对提高下肢动脉造影成像质量的应用价值。方法 前瞻性连续选取符合纳入标准的34例下肢动脉硬化闭塞症（LEAOD）患者，其中17例为研究组，接受宝石CT能谱模式扫描检查；另17例为对照组，接受64排螺旋CT扫描检查。通过计算获得研究组扫描图像中最佳单能量图，分别测量两组图像中髂总动脉、股浅动脉、腘动脉及胫前动脉中段平面CT 值及背景噪声（BN）值，计算出相应对比噪声比（CNR），以此对图像质量进行客观评价；同时2 名资深影像诊断医师采用双盲法对两组图像质量作5分制主观评分。结果 客观评价显示，研究组最佳单能量图能量水平集中在58～67 KeV，图像中髂总动脉、股浅动脉、腘动脉及胫前动脉CT值及CNR均明显高于对照组，其中CT值分别提高17.6%、12.2%、12.3%、35.2%，差异有统计学意义（t=2.818、1.636、1.119、2.907， P＜0.01）；CNR分别提高44.3%、40.8%、59.5%、105.8%，差异有统计学意义（t=3.729、4.686、4.294、5.213， P＜0.01）。主观评价显示，研究组、对照组图像质量评分在医师1分别为82分、69分，医师2分别为81分、68分，两组差异均有统计学意义（P＜0.01）；2名医师对图像质量评估一致性较好（K=0.85）。结论 下肢动脉CTA检查中，宝石能谱CT最佳单能量图显示狭窄段血管、远端小血管及去除硬化伪影能力较64排螺旋CT有明显提高，对下肢动脉腔内成形术术前和术后评估具有重要临床意义。
Objective To investigate the application of spectral CT optimal single energy image in improving the imaging quality of lower extremity angiography. Methods Thirty- four patients with lower extremity atherosclerotic occlusive disease, which met the inclusion criteria, were enrolled in this prospective study, and the patients were randomly divided into the study group （n=17） and the control group （n=17）. Gemstone spectral CT scan was employed for the patients of the study group, while 64-slice spiral CT scan was adopted for the patients of the control group. Through calculation, the optimal single energy images in the study group were obtained. The CT values, background noise （BN） values at the middle planes of the iliac artery, femoral artery, popliteal artery and anterior tibial artery in the two groups were separately measured, and the corresponding contrast noise ratios （CNR） were calculated, based on which the image quality was objectively evaluated. Using double-blind method the image quality was subjectively evaluated by two senior imaging diagnostic radiologists with 5-point grading method. Results Objective evaluation showed that in the study group the optimal single energy was 58- 67 KeV. The CT values and CNR of iliac artery, femoral artery, popliteal artery and anterior tibial artery of the study group were obviously higher than those of the control group. Among them, the CT values were increased by 17.6%, 12.2%, 12.3% and 35.2% respectively, the differences were statistically significant （t=2.818, t=1.636, t=1.119 and t=2.907 respectively, P〈0.01）. The CNRs were increased by 44.3%, 40.8%, 59.5% and 105.8%respectively, the differences were statistically significant （t=3.729, t=4.686, t=4.294 and t=5.213, P〈0.01）. The subjective evaluation results indicated that the image scores of the study group and the control group were 82 points and 69 points respectively measured by one radiologist, which were 81 points and 68 points respectively measured by another radiologist; the differences between the two groups were statistically significant （P〈0.01）. The consistency of assessment between the two radiologists was good （K=0.85）. Conclusion For lower extremity CT angiography, spectral CT optimal single energy image is superior to 64-slice spiral CT in displaying narrowed blood vessels, distal small blood vessels as well as in eliminating hardening artifacts, which is of great clinical significance for preoperative and postoperative assessment of lower extremity endovascular angioplasty.
出处
《介入放射学杂志》
CSCD
北大核心
2016年第11期997-1001,共5页
Journal of Interventional Radiology
基金
国家自然科学基金(81171433)
国家自然科学基金青年项目(81501523)
江苏省科技厅面上项目(BK20151423)
关键词
能谱CT
最佳单能量图
下肢动脉造影
下肢动脉硬化闭塞症
对比剂
spectral CT
optimal single energy image
lower extremity angiography
lower extremity atherosclerotic occlusive disease
contrast media
