探讨肾盂内积液与肾皮质的灰度比值在鉴别脓性肾积水与无感染性肾积水中的应用价值。

回顾性分析2016年1月至2020年6月在苏州大学附属第一医院超声科行肾穿刺造瘘术的119例患者的临床及影像检查资料，其中脓性肾积水患者52例，无感染性肾积水患者67例。采用Adobe Photoshop图像处理软件的“直方图”功能分别计算脓性肾积水、无感染性肾积水与肾皮质的灰度比值，采用t检验分析比较二者差异；绘制受试者操作特征（ROC）曲线分析灰度比值预测脓性肾积水的诊断效能。

脓性肾积水与肾皮质的灰度比值高于无感染性肾积水与肾皮质的灰度比值（0.65±0.29 vs 0.23±0.16），差异具有统计学意义（t=5.208，P＜0.001）。ROC曲线分析显示，当灰度比值为0.205时，其鉴别诊断脓性肾积水与无感染性肾积水的敏感度为90.9%，特异度为74.1%，曲线下面积为0.869。

灰度比值在脓性肾积水与无感染性肾积水的鉴别诊断中具有一定的临床应用价值。

To assess the application value of ultrasound gray scale ratio in the differential diagnosis of pyonephrosis and hydronephrosis.

The clinical and imaging data of 119 patients who underwent nephrostomy at the Ultrasound Department of the First Affiliated Hospital of Soochow University from January 2016 to June 2020 were retrospectively analyzed, including 52 patients with pyonephrosis and 67 patients with hydronephrosis. The ultrasound gray scale ratio of pyonephrosis and hydronephrosis to the renal cortex was calculated using the histogram of Adobe Photoshop software, and the difference was compared. The diagnostic efficiency of ultrasound gray scale ratio in predicting pyonephrosis was assessed by receiver operating characteristic (ROC) curve analysis.

The ultrasound gray scale ratio of pyonephrosis and hydronephrosis to the renal cortex was 0.65±0.29 and 0.23±0.16, respectively, and the difference was statistically significant (t=5.208, P＜0.001). According to the ROC curve analysis, when the ultrasound gray scale ratio was 0.205, the sensitivity, specificity, and area under the curve in the differential diagnosis of pyonephrosis and hydronephrosis were 90.9%, 74.1%, and 0.869, respectively.

The ultrasound gray scale ratio has appreciated value in the differential diagnosis of pyonephrosis and hydronephrosis.