Value of Endobronchial Ultrasound Elastography in Diagnosis of Central Lung Lesions

BACKGROUND Ultrasound elastography is an imaging modality used to show tissue stiffness in tumor pathophysiological processes that promote the formation of stiffer tissues. Endobronchial ultrasound (EBUS) elastography is an ultrasound elastography-based technique for measuring tissue stiffness during EBUS-guided transbronchial needle aspiration (EBUS-TBNA). The diagnostic value of EBUS elastography in central lung lesions remains largely unknown. MATERIAL AND METHODS A total of 57 patients with central lung lesions underwent ultrasonic bronchoscope examination. EBUS with standard B mode evaluation and elastography with grading score measurement were performed before EBUS-guided transbronchial needle aspiration (EBUS-TBNA). Comparison of the diagnosis accuracy in malignant lung lesions between elastography and standard EBUS was made. RESULTS Our data showed that the hypoechoic lesions, uneven echo, distinct boundary, and no air bronchogram were significant indicators of standard EBUS in diagnosis of malignant lung lesions (P<0.01). The differences in elastosonography grading scores between the benign and malignant lung lesions were statistically significance (P<0.01), and the elastography grading score was more sensitive and specific than the standard EBUS criteria in diagnosing malignant lung lesions. The area under the receiver operating characteristic curve (ROC) for the elastography grading score was 0.793. The best cut-off point of the elastography grading score for distinguishing malignant from benign lung lesions was 2.5. The elastography grading score had a sensitivity of 72.2%, specificity of 76.2%, positive predictive value of 83.4%, and negative predictive value of 61.5% for distinguishing malignant from benign lung lesions. The overall accuracy of elastography grading score was 73.7%. CONCLUSIONS BUS elastography can effectively diagnose central lung lesions. The diagnostic accuracy of elastography in malignant lung lesions is higher than that of standard EBUS criteria.