Clinical value of contrast-enhanced ultrasound in improving diagnostic accuracy rate of transthoracic biopsy of anteriormedial mediastinal lesions

Objective： To evaluate the clinical value of contrast-enhanced ultrasound（CEUS） in transthoracic biopsy of anterior-medial mediastinal lesions.Methods： A total of 123 patients with anterior or middle mediastinum lesions required ultrasound guided transthoracic biopsy for pathological diagnosis. Among them, 72 patients received CEUS examinations before biopsy. After CEUS, 8 patients were excluded from biopsy and the rest 64 patients underwent biopsy（CEUS group）. During the same period, 51 patients received biopsy without CEUS examination（US group）. The ultrasonography characteristics, the number of biopsy puncture attempts, diagnostic accuracy rate and the incidence of complications were recorded and compared between the two groups.Results： A large portion of necrosis area or superficial large vessels was found in 8 patients, so the biopsy was cancelled. The internal necrosis was demonstrated in 43.8% of the lesions in CEUS group and in 11.8% of US group（P0.001）. For thymic carcinoma, CEUS increased the detection rate of internal necrosis and pericardial effusion than conventional ultrasound（62.5% vs. 18.8%, P=0.012; 56.3% vs. 12.5%, P=0.023）. The average number of punctures in CEUS group and US group was 2.36±0.70 and 2.21±0.51 times, respectively（P0.05）. The diagnostic accuracy rate of biopsy in CEUS group（96.9%, 62/64） was significantly higher than that in US group（84.3%, 43/51）（P=0.022）. In US group, 2 patients suffered from mediastinal bleeding（3.9%）, while no major complications occurred in CEUS group.Conclusions： CEUS examination provided important information before transthoracic mediastinum biopsy and improved diagnostic accuracy rate in biopsy of anterior and middle mediastinum lesions than conventional ultrasound.