扩张与无扩张Riolan动脉弓的CT血管成像表现及临床意义

Manifestation and Significance of Normal and Dilated Riolan’s Arch on CT Angiography

目的探讨扩张与无扩张Riolan动脉弓的CT血管成像（CTA）表现、显示率及临床意义。资料与方法 75例患者行全腹部多层螺旋CTA,采用容积再现（VR）、最大密度投影（MIP）对肠系膜上动脉（SMA）、肠系膜下动脉（IMA）之间的Riolan动脉弓进行重建、观察及测量。结果多层螺旋CTA显示Riolan动脉弓共38例（50.7%）。其中扩张的Riolan动脉弓6例（8.0%）;均有动脉粥样硬化,IMA完全闭塞3例,IMA狭窄3例;SMA狭窄2例,SMA正常4例。Riolan动脉弓血管管径2.50~5.27mm,平均（3.83±0.60）mm。无扩张Riolan动脉弓32例（42.7%）;MIP图像上其吻合部细小蜿蜒,呈半开放状态,相应SMA与IMA均无狭窄扩张,Riolan动脉弓血管管径0.5~1.5mm。结论多层螺旋CTA能显示扩张的Riolan动脉弓及血管狭窄、闭塞情况,以及部分无扩张Riolan动脉弓的吻合部,对临床治疗方案的制订有重要参考价值;VR与MIP结合可提高无扩张Riolan动脉弓的显示率。

Purpose To study the CT angiography （CTA） manifestations, display and significance of normal and dilated Riolan＇s arch. Materials and Methods Seventy-five patients underwent abdomen multi-slice CTA （MSCTA）. Volume rendering （VR） and maximum intensity projection （MIP） were reconstructed to measure the normal and dilated Riolan＇s arch between SMA and IMA. Results CTA demonstrated Riolan＇s arch in 38 patients （50.7%）, including 6 （8.0%） dilated Riolan＇s arch and 32 （42.7%） normal Riolan＇s arch. Among 6 cases of dilated Riolan＇s arch with atherosclerosis, 3 were total occlusion and 3 were stenosis of IMA; 2 were SMA stenosis and 4 were normal SMA. The diameter of Riolan＇s arch was 2.50-5.27 mm, mean of （3.83±0.60） mm. In 32 cases with normal Riolan＇s arch, MIP demonstrated the half-opened paracolic arcade run between SMA and IMA with no stenosis or occlusion, the diameter of Riolan＇s arch was 0.5-1.5 mm. Conclusion MSCTA can clearly visualize the dilated Riolan＇s arch in multiple abnormalities with significant stenosis or occlusion in mesenteric circulation, and some normal Riolan＇s arch. Combining VR and MIP can better display normal Riolan＇s arch.