摘要目的 探讨多排螺旋CT检查血管成像和图像融合技术对腹腔镜直肠癌根治术的术前评估价值.方法 采用回顾性描述性研究方法.收集2018年2月至2019年3月南京医科大学附属无锡第二医院收治的60例行腹腔镜直肠癌根治术患者的临床病理资料;男39例,女21例;平均年龄为67岁,年龄范围为45～ 81岁.患者术前均行腹部多排螺旋CT平扫和双期增强扫描,将CT检查原始图像采用多平面重建进行观察,采用容积再现对动脉、静脉血管分别进行三维重建;密度差异较大的动脉血管,通过阈值分割、直接提取的方法获得;密度差异较小的静脉血管,通过区域生长方法获得;针对动脉、静脉血管添加红色、蓝色伪彩后进行图像融合,得到重建的血管三维图像.60例患者均由同一手术团队行腹腔镜直肠癌根治术,术中裸化血管后明确肠系膜下动脉(IMA)及其分支,包括左结肠动脉(LCA)、乙状结肠动脉(SA)、直肠上动脉(SRA)的实际解剖走行.观察指标:(1)IMA、LCA、SA、SRA在血管三维图像中的解剖走行及其与术中实际解剖走行的吻合情况.(2)IMA第一分支情况以及血管三维图像中IMA根部至其第一分支和至腹主动脉分叉点的距离.(3)CT检查二维图像及血管三维图像中IMA根部水平层面LCA与肠系膜下静脉(IMV)的空间关系.计量资料以Mean±SD表示,计数资料以绝对数和(或)百分比表示.结果 (1)IMA、LCA、SA、SRA在血管三维图像中的解剖走行及其与术中实际解剖走行的吻合情况:60例患者血管三维图像中IMA、LCA、SA、SRA的解剖走行为:Ⅰ型(直乙共干型)31例(51.7％);Ⅱ型(左乙共干型)9例(15.0％);Ⅲ型(3支共干型)18例(30.0％);Ⅳ型(无左型)2例(3.3％).血管三维图像中IMA、LCA、SA、SRA的解剖走行与术中镜下裸化血管后实际观察到的IMA、LCA、SA、SRA解剖走行吻合率为100.0％(60/60).(2)IMA第一分支情况以及血管三维图像中IMA根部至其第一分支和至腹主动脉分叉点的距离:60例患者IMA第一分支为LCA 49例(81.7％),为SRA和(或)SA 11例(18.3％);血管拉直重建图像中,IMA根部至其第一分支和腹主动脉分叉点的距离分别为(41±6)mm和(42±7) mm.(3)CT检查二维图像及血管三维图像中IMA根部水平层面LCA与IMV的空间关系:60例患者中,排除2例Ⅳ型(无左型)后,58例CT检查二维图像中,IMA根部水平层面LCA紧贴IMV 39例(67.2％),LCA远离IMV 19例(32.8％).58例患者血管三维图像中,IMA根部水平层面LCA位于IMV腹侧37例(63.8％),LCA位于IMV背侧21例(36.2％).结论 多排螺旋CT检查血管成像和图像融合技术可以直观地显示IMA及其分支的解剖走行,具有较高的临床应用价值.

abstractsObjective To explore the value of computed tomography angiography (CTA) and image fusion technology in preoperative evaluation of laparoscopic radical resection of rectal cancer.Methods The retrospective and descriptive study was conducted.The clinicopathological data of 60 patients who underwent laparoscopic radical resection of rectal cancer in the Mfiliated Wuxi Second People's Hospital of Nanjing Medical University from February 2018 to March 2019 were collected.There were 39 males and 21 females,aged from 45 to 81 years,with an average age of 67 years.All patients underwent abdominal multi-slice spiral computed tomography (CT) plain scan and dual-phase enhanced scan before operation.The original CT images were observed by multiplanar reconstruction and performed three-dimensional (3D) reconstruction of blood vessels by volume rendering.The CT images of arterial vessels with large density difference were abstracted by threshold segmentation and direct abstraction,and the CT images of venous vessels with small density difference were abstracted by region growing method.Then the 3D images of blood vessels were obtained after image fusion with red and blue pseudocolor added.All the 60 patients were performed laparoscopic radical resection of rectal cancer by the same surgical team,and were identified inferior mesenteric artery (IMA) and branches after being bared vessels,including anatomic course of left colonic artery (LCA),sigmoid artery (SA),and superior rectal artery (SRA).Observation indicators:(1) anatomic courses of IMA,LCA,SA,and SRA on the 3D images and their consistency with intraoperative anatomic courses;(2) the first branch of IMA and the distances from the root of IMA to the first branch and from the root of IMA to bifurcation point of the abdominal aorta on 3D images of blood vessels;(3) the spatial relationship between the horizontal level of LCA and the inferior mesenteric vein (IMV) on the 2D CT images and 3D images of blood vessels.Measurement data were represented as Mean±SD,and count data were represented as absolute numbers and percentages.Results (1) Anatomic courses of IMA,LCA,SA and SRA on the 3D images and their consistency with intraoperative anatomic courses:of the 60 patients,31 (51.7％) had type Ⅰ anatomic course of IMA on the 3D images,with LCA and SA from the common trunk;9 (15.0％) had type Ⅱ,with LCA and SA from the common trunk;18 (30.0％) had type Ⅲ,with LCA,SA,and SRA from the common trunk;2 (3.3％) had type Ⅳ,with no LCA.The consistency of anatomic courses of IMA,LCA,SA,and SRA on the 3D images with intraoperative anatomic courses of bared IMA,LCA,SA,and SRA was 100.0％ (60/60).(2) The first branch of IMA and the distances from the root of IMA to its first branch and from the root of IMA to the bifurcation point of abdominal aorta on 3D images of blood vessels:of the 60 patients,49 (81.7％) had LCA as the first branch of IMA,11 (18.3％) had SRA or SA as the first branch of IMA.The distances from the root of IMA to its first branch and from the root of IMA to the bifurcation point of abdominal aorta on 3D images of blood vessels were (41±6)cm and (42±7)cm.(3) The spatial relationship between the horizontal level of LCA and the IMV on the 2D CT images and 3D images of blood vessels:two patients of type Ⅳ were excluded from the 60 patients.On the 2D CT images of the rest 58 patients,39 (67.2％) had LCA adjacent to IMV and 19 (32.8％) had LCA distal to IMV at the horizontal level of IMA root.On the 3D images of blood vessels in the rest 58 patients,37 (63.8％) had the LCA located at the ventral side of IMV,and 21 (36.2％) had the LCA located at the dorsal side of the IMV.Conclusion Muiti-slice CTA and image fusion technology can visually display the anatomic course and variation of IMA and its branches,which has high clinical application value.