高帧率超声造影在鉴别浅表淋巴结良恶性中的临床价值

Clinical value of high frame rate contrast-enhanced ultrasound in differentiating benign and malignant superficial lymph nodes

目的应用高帧率超声造影观察浅表淋巴结增强均匀性和灌注方向,探讨其鉴别良恶性淋巴结的临床价值。方法选取我院经病理证实的浅表淋巴结异常患者121例(共121枚淋巴结),根据淋巴结大小分为A组37例(最大径0.5~1.0 cm)、B组56例(最大径>1.0~2.0 cm)、C组28例(最大径>2.0 cm),均行常规帧率及高帧率超声造影并保留其对应的动脉期图像,然后启动微血流增强模式,以1/3~1/2倍速播放并留存动态图像,分析两种造影帧率下各组良恶性浅表淋巴结增强均匀性和灌注方向的差异。绘制受试者工作特征(ROC)曲线分析常规帧率及高帧率超声造影鉴别不同大小良恶性浅表淋巴结的诊断效能。结果常规帧率和高帧率超声造影显示121例良恶性浅表淋巴结增强均匀性比较差异均有统计学意义(均χ^(2)=14.546,均P<0.001);常规帧率和高帧率超声造影显示良恶性浅表淋巴结灌注方向比较差异均有统计学意义(χ^(2)=5.160、4.600,均P<0.05)。C组中良恶性浅表淋巴结增强均匀性比较差异有统计学意义(χ^(2)=9.614,P=0.002)。各组中良恶性浅表淋巴结灌注方向比较差异均有统计学意义(均P<0.05)。ROC曲线分析显示,高帧率超声造影及常规帧率超声造影鉴别良恶性浅表淋巴结的曲线下面积(AUC)均分别为0.852、0.740,差异有统计学意义(Z=2.640,P=0.008);其中A、B、C组高帧率超声造影与常规帧率超声造影鉴别良恶性浅表淋巴结的AUC分别为0.817和0.669、0.864和0.732、0.827和0.772。A组两种帧率超声造影的AUC比较差异有统计学意义(Z=2.101,P=0.036),B、C组两种帧率超声造影的AUC比较差异均无统计学意义(Z=1.509、0.797,P=0.131、0.425)。结论高帧率超声造影可以清晰显示良恶性浅表淋巴结的增强均匀性和灌注方向,具有较好的鉴别诊断价值。

Objective To observe the enhanced uniformity and the perfusion direction of superficial lymph nodes by high frame rate contrast-enhanced ultrasound,and to explore its clinical value in distinguishing benign and malignant lymph nodes.Methods A total of 121 patients with superficial abnormal superficial lymph nodes were selected in our hospital(totally 121 lymph nodes),according to the lymph node size,they were divided into 37 cases in group A(maximum diameter 0.5~1.0 cm),56 cases in group B(maximum diameter>1.0~2.0 cm)and 28 cases in group C(maximum diameter>2.0 cm).Conventional frame rate and high frame rate contrast-enhanced ultrasound were performed and the arterial phase images were obtained.Then the microflow enhancement mode was activated to play and save dynamic images at 1/3~1/2 speed.The difference of enhancement uniformity and perfusion direction of benign and malignant superficial lymph nodes in each group by two contrast frame rates was analyzed.Receiver operating characteristic(ROC)curve was drawn to analyze the diagnostic efficiency of conventional frame rate and high frame rate contrast-enhanced ultrasound in differentiating benign and malignant superficial lymph nodes with different sizes.Results There were significant differences in the enhancement uniformity between benign and malignant superficial lymph nodes in 121 patients(bothχ^(2)=14.546,both P<0.001).The perfusion direction of benign and malignant superficial lymph nodes was statistically significant between conventional frame rate and high frame rate contrast-enhanced ultrasound(χ^(2)=5.160,4.600,both P<0.05).In group C,there was a statistically significant difference in enhancement uniformity between benign and malignant superficial lymph nodes(χ^(2)=9.614,P=0.002).There were significant differences in perfusion direction between benign and malignant superficial lymph nodes with different size(all P<0.05).ROC curve analysis showed that the area under the curve(AUC)of high frame rate contrast-enhanced ultrasound and conventional frame rate contrast-enhanced ultrasound in differentiating benign and malignant superficial lymph nodes were 0.852 and 0.740,respectively,with statistical significance(Z=2.640,P=0.008).The AUC of high frame rate contrast-enhanced ultrasound and conventional frame rate contrast-enhanced ultrasound in groups A,B and C for differentiating benign and malignant superficial lymph nodes were 0.817 and 0.669,0.864 and 0.732,0.827 and 0.772,respectively.The AUC of the two frequencies in group A was statistically significant(Z=2.101,P=0.036),while in group B and C had no statistically significant difference(Z=1.509,0.797,P=0.131,0.425).Conclusion The enhanced uniformity and perfusion direction of benign and malignant superficial lymph nodes can be clearly demonstrated by high frame rate contrast-enhanced ultrasound,which has a good value in differential diagnosis.