Abstract：
OBJECTIVE: To validate whether the introduction of the ratio of the cross diameters on the transverse section of the appendix (RATIO) ≤ 1.18 is useful for improving the ultrasound diagnosis of acute appendicitis (AA).
METHODS: Data from 220 patients with AA and 110 patients with a normal appendix were retrospectively studied. The RATIO ≤ 1.18, maximal outer diameter (MOD) > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm were used for predicting AA. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated.
RESULTS: The RATIO ≤ 1.18, MOD > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm for predicting AA showed a sensitivity of 90, 100, and 90%; specificity of 79.1, 27.3, and 88.2%; and AUC of 0.845, 0.636, and 0.891, respectively. When comparing the outcomes between MOD > 6 mm and a combination of MOD > 6 mm and RATIO ≤ 1.18, the specificity and PPV increased from 27.3 to 88.2% and 73.3 to 93.8%, respectively (all P < 0.0001). The sensitivity and NPV decreased from 100 to 90% and 100 to 81.5%, respectively (all P < 0.0001). The AUC increased from 0.636 to 0.891 (P < 0.0001). When comparing the AUC of MOD > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm for predicting AA with the AUC in a previous study, there were no significant differences between each other (all P > 0.05).
CONCLUSIONS: Introducing the RATIO ≤ 1.18 for the evaluation of AA can improve the diagnostic performance and significantly increase specificity.
METHODS: Data from 220 patients with AA and 110 patients with a normal appendix were retrospectively studied. The RATIO ≤ 1.18, maximal outer diameter (MOD) > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm were used for predicting AA. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated.
RESULTS: The RATIO ≤ 1.18, MOD > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm for predicting AA showed a sensitivity of 90, 100, and 90%; specificity of 79.1, 27.3, and 88.2%; and AUC of 0.845, 0.636, and 0.891, respectively. When comparing the outcomes between MOD > 6 mm and a combination of MOD > 6 mm and RATIO ≤ 1.18, the specificity and PPV increased from 27.3 to 88.2% and 73.3 to 93.8%, respectively (all P < 0.0001). The sensitivity and NPV decreased from 100 to 90% and 100 to 81.5%, respectively (all P < 0.0001). The AUC increased from 0.636 to 0.891 (P < 0.0001). When comparing the AUC of MOD > 6 mm, and a combination of RATIO ≤ 1.18 and MOD > 6 mm for predicting AA with the AUC in a previous study, there were no significant differences between each other (all P > 0.05).
CONCLUSIONS: Introducing the RATIO ≤ 1.18 for the evaluation of AA can improve the diagnostic performance and significantly increase specificity.
摘要：
目的：验证在阑尾横截面上引入横径比（RATIO）≤1.18是否有助于提高急性阑尾炎（AA）的超声诊断。
方法：回顾性研究了220例AA患者和110例正常阑尾患者的数据。比值≤1.18,最大外径(MOD)>6mm,用比值≤1.18和MOD>6mm的组合预测AA。接收器工作特性曲线下的面积(AUC),灵敏度,特异性，计算阳性和阴性预测值(PPV和NPV)。
结果：比值≤1.18，MOD>6mm，RATIO≤1.18和MOD>6mm联合预测AA的敏感性分别为90%、100%和90%;特异性分别为79.1%、27.3%和88.2%;AUC分别为0.845、0.636和0.891。当比较MOD>6mm和MOD>6mm和比值≤1.18的组合结果时，特异性和PPV从27.3增加到88.2％和73.3增加到93.8％。分别(所有P<0.0001)。敏感度和净现值从100%下降到90%，从100%下降到81.5%，分别(所有P<0.0001)。AUC从0.636增加到0.891(P<0.0001)。当比较MOD>6mm的AUC时，并结合比值≤1.18和MOD>6mm来预测AA与先前研究中的AUC，相互之间差异无统计学意义(均P>0.05)。
结论：将RATIO≤1.18引入AA的评估可以提高诊断性能并显着提高特异性。
方法：回顾性研究了220例AA患者和110例正常阑尾患者的数据。比值≤1.18,最大外径(MOD)>6mm,用比值≤1.18和MOD>6mm的组合预测AA。接收器工作特性曲线下的面积(AUC),灵敏度,特异性，计算阳性和阴性预测值(PPV和NPV)。
结果：比值≤1.18，MOD>6mm，RATIO≤1.18和MOD>6mm联合预测AA的敏感性分别为90%、100%和90%;特异性分别为79.1%、27.3%和88.2%;AUC分别为0.845、0.636和0.891。当比较MOD>6mm和MOD>6mm和比值≤1.18的组合结果时，特异性和PPV从27.3增加到88.2％和73.3增加到93.8％。分别(所有P<0.0001)。敏感度和净现值从100%下降到90%，从100%下降到81.5%，分别(所有P<0.0001)。AUC从0.636增加到0.891(P<0.0001)。当比较MOD>6mm的AUC时，并结合比值≤1.18和MOD>6mm来预测AA与先前研究中的AUC，相互之间差异无统计学意义(均P>0.05)。
结论：将RATIO≤1.18引入AA的评估可以提高诊断性能并显着提高特异性。
