颈部病变淋巴结实质区和坏死区表观扩散系数值的鉴别诊断价值

The ADC value of parenchyma and necrosis in cervical lymphadenopathy： differential diagnostic value

目的探讨淋巴结实质区和坏死区的表观扩散系数（ADC）值对颈部淋巴结病变的鉴别诊断价值。方法对36例颈部淋巴结转移癌、19例淋巴瘤和23例淋巴结结核患者进行扩散加权成像（DWI），测量并比较不同病变中淋巴结实质区和坏死区的ADC值，评价两者对3种淋巴结病变的鉴别诊断能力。共对病理（114枚）和临床随访（63枚）证实的177枚淋巴结进行ADC值的测量和分析，其中转移癌性淋巴结84枚，淋巴瘤性淋巴结40枚，结核性淋巴结53枚。2组均数的比较采用独立样本t检验，2组以上均数的比较采用单向方差分析（one-way ANOVA）。结果转移癌、淋巴瘤和结核的淋巴结实质区的ADC值分别为（0．93±0．16）、（0．64±0．13）和（1．01±0．11）×10^-3mm^3／s（F=82．928，p〈0．01），淋巴结转移癌和结核中淋巴结坏死区的ADC值分别为（2．02±0．36）、（1．25±0．15）×10^-3mm^2／s（t=12．045，P〈0．01）。当淋巴结实质区的ADC值≤0．77×10^-3mm^2／s时，诊断为淋巴瘤的敏感度、特异度分别为83％和89％。当淋巴结坏死区的ADC值≥1．60×10^-3mm^2／s时，诊断为淋巴结转移癌的敏感度、特异度分别为88％、100％。结论测量淋巴结的ADC值，尤其是坏死区的ADC值有助于淋巴结病变的鉴别诊断。

Objective To evaluate the apparent diffusion coefficient （ADC） of parenchyma and necrosis in distinguishing among metastatic lymph nodes, lymphoma and tuberculous lymph nodes. Methods Thirty-six patients with cervical lymph nodes metastasis from the head and neck squamous cell carcinomas, 19 patients with lymphoma and 23 patients with lymph nodes tuberculosis underwent diffusion-weighted imaging. The ADC values were measured and compared in parenchyma and necrosis of 177 lymph nodes confirmed by histopathology （ n = 114） and clinical follow-up （ n = 63 ）. The means between two groups were compared by t-test, and one-way analysis of variance （one-way ANOVA） was used to analyze the data among three or more groups. Results The mean ADC values of parenchyma in metastatic nodes, lymphoma and tuberculous nodes were （0. 93 ± 0. 16）×10^-3mm^2/s, （0. 64 ± 0. 13）×10^-3mm^2/s and （1.01 ± 0. 11 ）×10^-3mm^2/s respectively （ F = 82. 928, P 〈 0. 01 ） ; the ADC values of necrosis in metastatic and tuberculous nodes were （2. 02 ± 0. 36） ×10^-3mm^2/s and （ 1.25 ± 0. 15 ） ×10^-3mm^2/s respectively （ t = 12. 045, P 〈 0. 01 ）. An ADC value of parenchyma lower than or equal to 0. 77×10^-3mm^2/s was used as the threshold for lymphoma, with a sensitivity 83% and specificity of 89%. An ADC value of necrotic area greater than or equal to 1.60×10^-3mm^2/s was used as the threshold for metastatic nodes, with a sensitivity of 88% and specificity of 100%. Conclusion The ADC value of lymph nodes, especially for their internal necrotic areas, can help judge the nature of the cervical lymph nodes.