Experimental study on CT lymphography in evaluating axillary sentinel lymph nodes of rabbit's breast cancer using 3D and curved planar reformation / 实用放射学杂志

ABSTRACT

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.