Quantification analysis of pleural line movement for the diagnosis of pneumothorax

BACKGROUND There is no research on quantitative pleural line movement. In this study, we assume that tissue Doppler and its quantitative technology can quantify the pleural line movement and can be used to diagnose pneumothorax. AIM To evaluate the quantitative assessment of pleural line movement measured by tissue Doppler imaging (TDI) for pneumothorax diagnosis. METHODS Adult patients (n = 45) diagnosed with unilateral pneumothorax were included in this study. Each patient underwent TDI of both lungs. The pneumothorax side and contralateral normal lung side were compared using several indices obtained from TDI: peak pleural line velocity (PVmax), peak chest wall tissue velocity (CVmax), peak pleural line strain value (PSmax), peak chest wall tissue strain value (CSmax), PVmax/CVmax and PSmax/CSmax. The receiver operating characteristic analysis was used to evaluate the performance of these quantitative assessments for pneumothorax diagnosis. RESULTS Various quantitative variables of the pneumothorax side were all lower than that of the non-pneumothorax side and included the PVmax (0.36 cm/s vs 0.59 cm/s, P < 0.001), PSmax (1.14% vs 1.90%, P = 0.001), PVmax/CVmax (1.06 vs 4.93, P < 0.001), and PSmax/CSmax (0.76 vs 1.74, P < 0.001). For the discrimination of pneumothorax, the cut-off values of the PVmax, PSmax, PVmax/CVmax, and PSmax/CSmax were calculated as 0.50 cm/s, 0.94%, 1.96, and 1.12, respectively. Similarly, the sensitivities and specificities of PVmax, PSmax, PVmax/CVmax, and PSmax/CSmax were 96% and 62%, 47% and 91%, 93% and 96%, and 82% and 93%, respectively. The area under the receiver operating characteristic curve were 0.84, 0.72, 0.99, and 0.91, respectively, for PVmax, PSmax, PVmax/CVmax, and PSmax/CSmax. CONCLUSION Quantification analysis of pleural line movement using TDI is a useful tool for the diagnosis of pneumothorax.