经直肠实时组织弹性成像技术鉴别诊断前列腺良恶性病变的价值

目的探讨经直肠实时组织弹性成像技术在鉴别诊断前列腺良、恶性病变中的应用价值。方法选择2012年5月至2013年1月南京大学医学院附属鼓楼医院经病理证实的88例前列腺病变患者95个病灶，采用经直肠实时组织弹性成像技术测量超声弹性分级和应变率比值。以病理结果作为金标准，计算弹性分级法诊断前列腺良、恶性病变的敏感度、特异度和准确性；绘制弹性分级法和应变率比值法的受试者操作特性（ROC）曲线。采用，检验比较弹性分级法和应变率比值法诊断前列腺良、恶性病变的准确性。结果95个前列腺病灶中病理诊断为良性47个，恶性48个。95个前列腺病灶超声弹性分级Ⅰ级26个，Ⅱ级19个，Ⅲ级16个，Ⅳ级21个，Ⅴ级13个。以超声弹性分级≤Ⅱ级诊断为良性，≥Ⅲ级诊断为恶性，超声弹性分级法诊断前列腺良、恶性病变的准确性为76．84％（73，95）、敏感度为79．17％（38／48）、特异度为74．47％（35／47）。ROC曲线显示，应变率比值法鉴别诊断前列腺良、恶性病变的最佳阈值为4．67、约登指数为0．622、敏感度为83．33％、特异度为78．72％、准确性为81．05％；弹性分级法ROC曲线下面积为0．830，应变率比值法ROC曲线下面积为0．877。应变率比值法诊断前列腺良、恶性病变的准确性略高于弹性分级法，但差异无统计学意义（χ^2=0．51，P〉0．05）。结论经直肠实时组织弹性成像技术对前列腺良、恶性病变的鉴别诊断具有一定的价值，有助于前列腺癌的诊断。

The value of transrectal realtime tissue elastography in the differential diagnosis of prostatic lesions

Objective To assess the contribution of transrectal realtime tissue elastography （TRTE） on the differential diagnosis of prostatic diseases. Methods A total of 88 prostatic disease patients with 95 lesions proved by pathology from May 2012 to January 2013 in the Affiliated Drum Tower Hospital of Medical College of Nanjing University were included. The elasticity grade and strain ratio were calculated by using TRTE. According to the gold standard of pathological results, the sensitivity, specificity, accuracy rate were calculated to evaluate the effectiveness of elasticity grade and strain ratio in distinguishing benign and malignant prostatic diseases; and the receiver operating characteristic （ROC） curves were made respectively. The accuracy of elasticity grade and strain ratio in diagnosing prostatic diseases was also compared using chi-square test. Results Forty-seven benign lesions were found in the 95 prostatic lesions and the other 48 lesions were malignant. The elasticity grades of the 95 prostatic lesions were as follows： Grade Ⅰ 26, Grade Ⅱ 19, Grade Ⅲ 16, Grade Ⅳ 21, and Grade Ⅴ 13. Elasticity grade ≤Ⅱ was considered to be benign, while grade ≥ Ⅲ was malignant. The sensitivity, specificity, accuracy rate of elasticity grade in diagnosis of prostatic malignant lesions was 79.17% （38/48）, 74.47% （35/47） and 76.84% （73/95）, respectively. According the ROC curve analysis, the cutoff point of strain ratio was 4.67, and Youden＇s index was 0.622. The sensitivity, specificity, accuracy rate of strain ratio was 83.33%, 78.72% and 81.05%, respectively. The area under ROC curves of strain ratio was superior to that of elasticity grade. But the diagnosis accuracy of the two approaches was almost the same in statistics （χ^2=0.51, P 〉 0.05）. Conclusions TRTE is valuable in the differential diagnosis of the prostatic benign and malignant lesions. Both strain ratio and elasticity grade are useful approaches, and have similar diagnostic accuracy.