BACKGROUND The tuberculin-purified protein derivative (PPD) test is commonly used as a screening tool for tuberculosis (TB). However, the traditional judgment standard of the PPD test is influenced by subjective factors, which can lead to less accurate and intuitive test results. OBJECTIVES To evaluate the accuracy of ultrasonography as a novel auxiliary judgment method for the tuberculin-PPD test and its clinical application. DESIGN This study was designed as a comparative study following the STROBE guidance. METHODS From February to May 2022, 208 patients with active tuberculosis infection were enrolled. Manual judgment and ultrasonography were employed in a double-blind-utilized manner, and the PPD examination results were recorded. Kappa statistic was performed to measure the concordance between the two diagnostic methods. Fisher's exact test was used for the analyses of the PPD test results of all 208 active tuberculosis infection patients' PPD results. RESULTS There was a significant difference between the two methods in the PPD result judgment (p < 0.001), particularly in the positive ratio of the PPD test results, (p < 0.05). Overall, 50 patients were determined as PPD positive based on manual judgment. However, only 24 patients' PPD test results were determined as positive via ultrasonography. The remaining 26 patients should have been classified as strong positive but were misclassified as positive. The misdiagnosis ratio was 52% (26/50). CONCLUSION Ultrasonography has superior accuracy to traditional manual judgment. Moreover, it does not rely on sophisticated clinical experience or training and can reveal subtle changes of the skin corresponding to each PPD test result providing intuitive results. In conclusion, ultrasonography can be used as an auxiliary interpretive approach for PPD test and has a promising future for clinical application.

中文翻译：

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超声检查——结核菌素纯化纯蛋白衍生物皮肤试验的一种新的辅助解释方法：一项比较研究。

背景技术结核菌素纯化蛋白衍生物（PPD）测试通常用作结核病（TB）的筛查工具。然而，传统的PPD测试判断标准受主观因素影响，导致测试结果不太准确和直观。目的评价超声检查作为结核菌素-PPD试验辅助判断新方法的准确性及其临床应用。设计本研究被设计为遵循 STROBE 指南的比较研究。方法 2022年2月至5月，纳入208例活动性结核感染患者。采用人工判断和超声检查双盲的方式，记录PPD检查结果。进行 Kappa 统计来衡量两种诊断方法之间的一致性。采用Fisher精确检验对全部208例活动性结核感染患者的PPD检测结果进行分析。结果 两种方法在PPD结果判断上存在显着性差异（p < 0.001），尤其是PPD测试结果的阳性率（p < 0.05）。总体而言，根据人工判断，50名患者被确定为PPD阳性。然而，只有 24 名患者的 PPD 检测结果通过超声检查确定为阳性。其余26名患者本应被分类为强阳性，但却被错误分类为阳性。误诊率为52%（26/50）。结论超声检查比传统的人工判断具有更高的准确性。而且，它不依赖复杂的临床经验或培训，可以揭示每个PPD测试结果对应的皮肤的细微变化，提供直观的结果。综上所述，超声检查可作为PPD检测的辅助解释手段，具有良好的临床应用前景。