64层螺旋CT血管造影图像融合技术对血液透析动静脉内瘘功能不全的评价

目的：探讨64层螺旋CT血管造影（64-MSCTA）图像融合技术在血液透析患者动静脉内瘘功能不全评估中的临床应用价值。方法：32例自体动静脉内瘘（AVF）和4例人工血管动静脉内瘘（AVG）功能不全的患者进行血管造影检查后，分别使用最大密度投影（MIP）、容积成像（VR）、曲面重建（CPR）及多平面重建（MPR）等技术对扫描数据进行三维重建，采用VR技术分别重建动脉流入道、静脉流出道（对于AVG患者还包括人工血管），并使之相融合，观察动静脉内瘘血管的显示情况。结果：32例自体AVF中，吻合口狭窄11例，轻度、中度、重度及闭塞分别为1例、1例、8例及1例；流出静脉狭窄18例，轻度、中度、重度及闭塞分别为2例、4例、8例及4例；流入动脉狭窄5例，轻度2例、重度3例。32例自体AVF中合并附壁血栓11例，静脉瘤样扩张13例，侧支循环形成9例，吻合口及流出静脉多发钙化斑2例。4例人工血管AVG中，单纯静脉吻合口端狭窄2例，轻度及中度各1例；人工血管轻度节段性狭窄1例；吻合口及人工血管同时狭窄1例。结论：64-MSCTA图像融合技术能清楚准确地显示内瘘血管解剖空间结构并对其进行评价，对指导临床进一步治疗有重要价值。

Assessment of 64-slice spiral computed tomography angiography with image fusion for failing arteriovenous fistulas and grafts in hemodialysis patients

Objective: To evaluate the clinical value of 64-multislice spiral computed tomography angiography (64-MSCTA) with image fusion for failing arteriovenous fistula in hemodialysis patients. Methods: Thirty-two hemodialysis patients with failing autogenous arteriovenous fistula (AVF) and 4 patients with failing synthetic arteriovenous graft (AVG) underwent 64-MSCTA. After axial source images were obtained, maximum intensity projection (MIP), volume rendering (VR), curved planner reconstruction (CPR), multiple planar reconstruction (MPR) images were constructed. Using VR technique, computed tomography angiography (CTA) of inflow artery and outflow vein (the polytetrafluoroethylene loop graft also was included in patients with AVG) were reconstructed respectively, and then the images were fused together. Results: Among 32 hemodialysis patients with failing AVF, the anastomotic stenosis in 11 cases, the cases of mild (0%～49%), moderate(50%～74%), severe (75%～99%) and occlusion (100%) stenosis were 1, 1, 8 and 1, respectively. Outflow vein stenosis was found in 18 cases, the cases of mild, moderate, severe and occlusion were 2, 4, 8 and 4, respectively. Inflow artery stenosis was found in 5 cases, mild in 2 and severe in 3. Mural thrombus was displayed by MIP in 11 cases, vein tumor-like expansion in 13 cases, multiple calcified plaques in 2 cases. Among 4 hemodialysis patients with AVG, 2 cases stenosis was at the venous anastomosis, mild in 1 and severe in 1. One cases stenosis was at PTEE loop graft and was of mild segmental stenosis. One case stenosis at anastomosis and loop graft simultaneously. Conclusion: 64-MSCTA with image fusion can accurately evaluate arteriovenous fistulas and grafts, which is helpful for customize future intervention.