宝石 CT 能谱成像在乳腺浸润性导管癌腋窝转移淋巴结诊断中的初步应用

目的：探讨宝石 CT 能谱成像（gemstone spectral imaging，GSI）在乳腺浸润性导管癌腋窝转移淋巴结诊断中的价值。方法：收集绵阳市中心医院2013年2月～2014年12月期间经病理证实并行 GSI 检查的乳腺浸润性导管癌患者32例，所有患者均行腋窝淋巴结清扫术。GSI 扫描时间为动脉后期（33s），图像后处理采用 ADW4．6工作站及 GSI-view 软件。根据手术病理结果将纳入研究的淋巴结分为转移组（15枚）和非转移组（62枚）。由软件自动生成 KeV-CT 值（电子千伏值-CT 值）曲线，同时记录每枚淋巴结的碘基值和相应层面主动脉碘基值、不同 KeV下淋巴结 CT 值和相应层面主动脉的 CT 值。计算每枚淋巴结40～70KeV 的斜率值（斜率 K ＝（HU40KeV-HU70KeV ）／30）、标化碘基值（淋巴结碘基值／主动脉碘基值）、不同 KeV 下的标化 CT 值（淋巴结 CT 值／主动脉 CT 值）。统计分析运用 spss17．0。结果：在40～70KeV 区间内，转移组淋巴结与非转移组淋巴结的 KeV-CT 值曲线斜率差异具有统计学意义（P ＜0．05）。转移组的碘基值、标化碘基值均小于非转移组，差异有统计学意义（P ＜0．05）。不同KeV 下标化 CT 值的差异均无统计学意义。以曲线斜率3．92作为诊断转移淋巴结的阈值时，灵敏度和特异度分别为77．4％、71．4％；以碘基值19．44作为诊断阈值时，灵敏度和特异度分别为73．3％、72．6％；以标化碘基值0．1677作为诊断阈值时，灵敏度和特异度分别为82．3％、80．0％。结论：CT 能谱成像作为一种新的无创性检查方法，对诊断乳腺浸润性导管癌腋窝转移淋巴结有重要价值。

Preliminary Study of Gemstone Spectral Imaging in the Diagnosis of Axillary Lymph Nodes Metastasis in Patients with Infiltrating Ductal Breast Carcinoma

Objective:To evaluate the clinical feasibility of gemstone spectral imaging(GSI)in the diagnosis of axillary lymph nodes metastasis in patients with infiltrating ductal breast carcinoma.Methods:Thirty-two cases of patho-logically proven infiltrating ductal breast carcinoma from Feb.2013 to Dec.2014 were included in this study.All cases un-derwent GSI scan in lateral artery phase (33s).Images were retrospectively analyzed using GSI viewer on ADW 4.6 work station.The axillary lymph nodes were classified as metastatic group (n =15)or non-metastatic group (n =62)according to the pathological diagnosis.The KeV-CT value curve was generated by the computer automatically,the iodine-based value and CT value of each lymph nodes and the corresponding strata of the artery were recorded.The slope of KeV-CT value curve [defined as:K =(HU40KeV HU70KeV)/30],normalized iodine-based value (lymph node iodine-based value /arterial iodine-based value),normalized CT values (lymph node CT value /arterial CT value)under different KeVs were compared between the metastatic and non-metastatic lymph nodes.Spss17.0 software was used for analysis and P <0.05 was considered statistically different.Results:The slope of KeV-CT value curve of axillary metastatic lymph nodes was sig-nificantly different from that of non-metastatic lymph nodes (P <0.05)in 40 ~70KeV area.The Iodine-based value and the normalized Iodine-based value of metastatic lymph nodes were significantly lower than those of the non-metastatic group (P <0.05).No statistically significant difference was found of the normalized CT value between the metastatic and non-metastatic group.When the threshold of the slope of KeV-CT value curve was set at 3.92,the sensitivity and specificity were 77.4% and 71.4%,respectively.When the threshold of the Iodine-based value was set at 19.44,the sensitivity and specificity were 73.3% and 72.6%,respectively.While sensitivity and specificity for the normalized Iodine-based value were 82.3% and 80.0%,respectively when the threshold of the nomarlized Iodine-based value was set at 0.1677.Conclu-sion:GSI as a new non-invasive examination,is an important way for the detection of axillary lymph nodes metastasis in patients with infiltrating ductal breast carcinoma.