摘要
目的探讨扩散加权成像（DWI）鉴别腋窝炎性增生性与转移性淋巴结的价值。方法40只健康雌性新西兰大白兔随机平均分成2组，分别建立腋窝炎性增生性和转移性淋巴结模型，建模成功后行常规MRI及DWI检查。观察两组淋巴结在MRI上的信号强度并于rr2wI上测量其数值，于T，WI、DWI和ADC图上分别测量并比较两组淋巴结与同层面背侧肌肉的相对信号强度（rSIrSI。）和相对表观扩散系数（rADC）值；应用受试者工作特性曲线（ROC）分析rADC值对良恶性淋巴结的鉴别诊断效能；以病理学为基础，分析两组淋巴结的rADC值与细胞密度的相关性。结果两组淋巴结的大小、rsIrSI。差异均无统计学意义。炎性淋巴结的rADC值高于转移性淋巴结，分别为0．91±0．14、0．644-0．18，两者间差异有统计学意义（t=3．879，P=0．03），但仍存在小部分重叠。当rADC值取最佳阈值0．780时，其诊断的敏感性和特异性分别为86．2％和74．4％。两组淋巴结的rADC值与细胞密度呈负相关（r=一0．53，P=0．003）。结论rADC值相对于常规MRI序列能更准确地鉴别淋巴结的良恶性，细胞密度可能是影响两组淋巴结rADC值差异的关键因素。
Objective To evaluate the value of diffusion-weighted imaging （DWI） in the differentiation of axillary inflammatory hyperplastic and metastatic lymph nodes. Methods Forty female New Zealand white rabbits were divided randomly into 2 groups （ n = 20 each）. And the animal models of axillary inflammatory hyperplastic and metastatic lymph nodes were established. All successfully implanted models received conventional magnetic resonance imaging （MRI） and diffusion-weighted imaging （DWI） examinations. The features of signal intensity and shapes of lymph nodes were observed in two groups. The sizes of lymph nodes were measured on the selected axial T2WI. The signal intensity and appearance diffusion coefficient （ADC） value of lymph nodes and dorsal muscle at the same slice were measured on the selected T2WI, DWI and ADC map respectively. The relative signal intensity （rSIr2wi, rSIvwI ） and relative ADC （rADC） value of lymph nodes to dorsal muscle were calculated and compared. The diagnostic efficacy of differentiating benign and mall .gnant lymph nodes was analyzed with rADC value through the receiver operating characteristic curve. The correlation between rADC value and cell density was assessed with pathological findings as reference standard. Results The differences of size, rSI2wl and rSIDwI were not statistically significant between two groups. The rADC value of inflammatory lymph nodes was greater than that of metastatic lymph nodes （0. 91 ＋ 0. 14 vs 0. 64 ＋ 0. 18 ）. Significant difference existed （t = 3. 879, P = 0. 03 ）. But there was a little overlap between two groups. With 0. 78 as the diagnostic threshold of rADC value, the sensibility and specificity was 86. 2% and 74.4% respectively. The correlation between rADC value and cell density of inflammatory hyperplastie and metastatic lymph nodes was significantly inverse （ r = - 0. 53, P = 0. 003 ）. Conclusion As compared with the routine MRI sequence, rADC value has a higher diagnostic efficacy in the differentiation
出处
《中华医学杂志》
CAS
CSCD
北大核心
2012年第9期592-595,共4页
National Medical Journal of China
基金
天津市卫生局科技基金（09KZl05）
关键词
磁共振成像
弥散
淋巴结
模型
动物
Diffusion magnetic resonance imaging
Lymph nodes
Models, animal
