中文摘要：

目的研究256层CT血管成像对于血液透析患者自体动静脉内瘘功能不全的的临床价值。方法采用256层CT对20例血液透析并血管通路功能不全患者进行造瘘侧上肢血管成像。从非患肢前臂静脉进针注射非离子型造影剂80～100mI。，速率为3～4．5mL／s。进针后利用造影剂浓度跟踪技术，设感兴趣区（ROI）位于主动脉弓，阈值为150HU，ROI到达阈值后18s启动扫描。2例患者扫描结束30s启动延迟期扫描。后期回顾性薄层重建采用标准算法，层厚0．625mm，间隔0．625mm，使用EBW工作站，分别使用曲面重建（CPR）、多平面重建（MPR），最大密度投影（MIP）及容积成像（VR）等技术对扫描数据进行三维重建，最后使用EBW工作站血管分析测量功能，对内瘘吻合口进行管腔截面测量，并与流入动脉进行狭窄度对比。结果20例患者共112个血管节段中，29个血管节段见狭窄，其中吻合口15个（51．7％），引流静脉前臂段8个（27．5％），引流静脉上臂段3个（10．3％），锁骨下静脉3个（10．3％）。5例患者侧支循环形成，引流静脉扩张lO例，9例流人动脉变异，肘部巨大血肿1例。结论上肢血管CTA可以精确地评价自体动静脉内瘘情况。对慢性肾衰竭内瘘功能不全患者的临床进一步处理有着指导作用。

英文摘要：

Abstract：Objective To evaluate the clinical value of CT angiography （CTA） using 256-slice CT scanner for autogenous arterio- venous fistula dysfunction in hemodialysis patients. Methods A total of 20 hemodialysis patients with autogenous arteriovenous fis- tula dysfunction underwent CTA of the affected upper limbs. A total of 80--100 mL of noniodinated contrast agent （iopamidol） was injected at a rate of 3--4.5 mL/s into the antecubital vein of contralateral limb. A contrast agent concentration tracking technology was utilized. Aortic arch was regarded as the region of interest （ROI） and the threshold was set at 150 HU. Imaging commenced af- ter a delay of 18 s when ROI arrived at the threshold. In two patients, the delay phase scanning was started at 30 s after the first scanning . The images were reconstructed with standard algorithm, with 0. 625 mm slice thickness and 0. 625 mm slice gap, using different postprocessing techniques such as surface reconstruction, multiple planar reconstruction, maximum intensity projection and volume rendering on the EBW workstation. The cross sectional area of the fistula anastomotic stoma was measured using the vessel analysis and measurement function of the EBW workstation, and compared with the supplying artery. Results The blood vessels in affected limb were clearly displayed on CTA. Of 94 vascular segments in 20 hemodialysis patients, 29 were of stenosis, including 15 at arteriovenous anastomotic stoma {51.7~） , 8 at venous outflow in forearm {27.5% }, 3 at venous outflow in upper arm （ 10.3~ ） and 3 at subclavian vein （10.3 ~）. Five cases exhibited collateral circulation formation; 10 had draining vein dilatation; 9 had suppl- ying artery variation and 1 had hematoma in the elbow. Conclusion Autogenous arteriovenous fistula can be accurately evaluated NNo by using CT angiography, which is helpful for guiding management clinically of the patients with chronic renal failure fistula dysfunction.