3D重建及CPR技术在乳腺癌腋窝前哨淋巴结CT淋巴管造影检查中的实验研究

目的 探讨多层螺旋CT 3D重建及曲面重建(CPR)技术在乳腺癌腋窝前哨淋巴结(SLN)CT淋巴管造影(CT-LG)检查中的应用价值.方法 采用VX2肿瘤组织块悬液皮下注射法制作VX2乳腺癌大白兔动物模型,对其行CT-LG检查.所有原始数据传至后处理工作站,运用3D重建及CPR技术显示显影的淋巴管及淋巴结,CT-LG图像上SLN定义为自对比剂注射部位至腋窝方向最先引流的淋巴结,并与SLN活检结果对照.结果 (1)20只荷瘤兔行CT-LG检查后,3D重建及CPR可显示SLN及其引流淋巴管;且70%(14/20)的实验兔成像效果良好,CT-LG共显示22条引流淋巴管,16枚SLN,7枚非SLN.(2)3D图像显示连续且对比剂充填均匀的8条淋巴管在CPR图像上均显示为均匀、连续的线管状高密度影;3D图像大部分显示对比剂充盈良好,局部中断或模糊的14条淋巴管,在CPR图像上均见自对比剂注射部位至腋窝SLN方向的连续的密度不均的线管状高密度影.余6只实验兔CT-LG检查显像效果较差,其中3只SLN显影淋巴管未显影,其CPR图像见自对比剂注射部位至SLN方向显影浅淡的线管状略高密度影,密度不均匀;而2只仅淋巴管起始段显影及1只SLN和淋巴管均未显影的实验兔,CPR图像与3D图像显像效果类似.(3)前哨淋巴结活检(SLNB)共摘取SLN 24枚,病理为转移性18枚,阴性6枚.淋巴结长径及CT-LG显像SLN出现充盈缺损在转移性和阴性SLN中有统计学差异(P=0.041和P=0.001);淋巴结短径、形状及边缘清晰与否在二者间无统计学意义(均P>0.05).结论 CT-LG检查中3D重建及CPR技术均可有效显示腋窝SLN及淋巴管的形态,且CPR技术显示更清楚、细致;淋巴结长径及CT-LG显像SLN的充盈缺损有助于鉴别转移性和阴性SLN.

Experimental study on CT lymphography in evaluating axillary sentinel lymph nodes of rabbit's breast cancer using 3D and curved planar reformation

Objective To study the value of CT lymphography (CT-LG) in evaluating axillary sentinel lymph nodes (SLN) of rabbit with breast cancer using 3D and curved planar reformation (CPR).Methods CT-LG examinations were completed on the VX2 rabbit models bearing breast cancer established by tumor tissue mass suspension injection.All raw data were transferred to a postprocessing workstation, then the 3D and CPR were used to show lymphatic vessel and lymph nodes.On the CT-LG images, one or several lymph nodes displayed firstly in the lymphatic drainage pathway was defined as the SLN which was then confirmed by the biopsy.Results (1) 20 rabbits bearing tumor underwnet CT-LG examinations, and both SLNs and draining lymphatic vessels were detected using 3D and CPR techniques.70% (14/20) of experimental rabbits had fine images, and 16 SLNs and 7 non-SLNs were demonstrated on 14 rabbits on CT-LG images with good quality.(2) 8 continuous lymphatic vessels displayed well, exhibiting a homogeneous and continuous tube with uniform contrast-medium filling on CPR images.Most lymphatic vessels demonstrated well, and the 14 vessels with local interrupt or fuzzy on 3D images showed continuous tubular contrast-filling with heterogeneous high-density on the CPR images from the injection sites to axillary SLN.Among 6 rabbits with poor images, 3 rabbits showed the SLN but without lymphatic vessels on 3D images, 2 showed only initial segment of lymphatic vessel,and 1 had no lymphatic vessel and SLN.(3) A total 24 SLNs were obtained by SLNB,including 18 metastatic SLNs and 6 negative ones.On CT-LG images, there were statistical differences between the metastatic and negative SLNs in the maximum diameter and filling defect (P=0.041 and P=0.001, respectively).However, the short diameter, shape and margin of SLNs had no statistical differences between the two groups (all P>0.05).Conclusion On CT-LG examinations, 3D and CPR images may show axillary SLNs and lymphatic vessels effectively,and CPR can demonstrate more details than 3D.The maximum diameter and fillingdefect of SLN are helpful for distinguishing metastatic and negative SLNs.