背景抑制弥散加权成像(DWIBS)在腹部淋巴结病变中的临床应用价值

Clinical value of diffusion-weighted with background suppression in lymph node diseases of abdomen

目的背景抑制弥散加权成像(diffusion-weighted whole body imaging with background body signal suppression,DWIBS)是一种高分辨的体部DWI技术。本文目的在于探讨DWIBS在腹部淋巴结病变鉴别诊断中的价值。方法对腹部共142枚经手术病理证实的淋巴结进行研究,包括恶性肿瘤淋巴结转移67枚,炎性增生31枚,淋巴瘤44枚。采用DWIBS序列扫描,测量病灶的表观扩散系数(apparent diffusion coefficient,ADC)值,比较腹部良性淋巴结、恶性肿瘤淋巴结转移、淋巴瘤ADC值是否具有显著性差异。采用诊断试验的ROC曲线分析确定ADC值的诊断阈值。结果 DWIBS对腹部淋巴结病变显示良好。良性淋巴结实质部分的ADC值为(1.31±0.09)×10-3mm2/s,恶性肿瘤转移淋巴结组为(0.94±0.71)×10-3mm2/s,淋巴瘤组为(0.61±0.16)×10-3mm2/s。三组平均值之间的差异具有统计学意义(P<0.05)。当以ADC值等于1.20×10-3mm2/s作为鉴别良恶性的诊断指标,其诊断价值为优(Az值=0.973,P<0.05),灵敏度为96.8%,特异度为91.0%。当以ADC值等于0.78×10-3mm2/s作为恶性肿瘤转移与淋巴瘤鉴别诊断的阈值时,诊断效果良好(Az值=0.901,P<0.05),灵敏度为88.1%,特异度为81.8%。良、恶性淋巴结坏死区之间的ADC值分别为(1.39±0.10)×10-3mm2/s和(1.35±0.10)×10-3mm2/s,两者间没有统计学差异(P<0.005)。结论 DWIBS在腹部淋巴结病变中具有良好的应用前景,ADC值可用于腹部淋巴结病变的鉴别诊断。

Objective This study was to investigate the value of diffusion weighted whole body imaging with background suppression （DWIBS） in differentiation between benign, malignant lymph nodes and lymphoma in abdominal lymph nodes （celiac and inguinal lymph nodes）. Methods DWIBS （b=1000） sequence records of 142 abdominal lymph nodes confirmed by operation and pathology were studied, including 67 intraperitoneal metastatic lymph nodes, 31 benign lesions and 44 lymphoma nodes. The apparent diffusion coefficients （ADC） of malignant lesions, benign lesions and lymphomas were compared. The diagnosis threshold between malignant and benign lesions was decided according to ROC curve. Results The mean ADC value of benign lymph nodes, metastatic lymph nodes and lymphomas were （1.31±0.09）×10^-3mm2/s, （0.94±0.17）×10^-3 mm2/s and （0.61±0.16）×10^-3 mm2/s respectively. There were significant differences among these ADC values（P〈0.05）.When an ADC value was less than 1.20×10^-3 mmZ/s, it was used as the threshold for metastatic nodes, where sensitivity of 96.8% and specificity of 91..0% were available and the diagnostic value was very good （Az=0.973, P〈0.05）.When an ADC value was less than 0.78 ×10^-3 mm2/s, it was used as the threshold for lymphomas,where sensitivity of 88.1% and specificity of 81.8 % were available and the diagnostic value was good （Az=0.931, P〈0.05）. Conclusion DWIBS may be applied to detect celiac lymph node diseases. ADC value may help to differentiate between benign and malignant abdominal lymph node lesions.