Sonographic septation: a predictor of sequela of tuberculous pleurisy after treatment

Yung-Fa Lai ¹, Mao-Chang Su ², Hsu-Huei Weng ³, Jiun-Ting Wu ¹ and Chien-Tung Chiu ^1*

¹ E-DA Hospital & I-SHOU University, Kaohsiung, Taiwan
² Chang Gung Memorial Hospital- Kaohsiung Medical Center , Kaohsiung, Taiwan
³ Chang Gung Memorial Hospital- Chia-Yi, Taiwan

^* To whom correspondence should be addressed. E-mail: chiuct168{at}gmail.com.

Accepted 20 May 2009

Abstract

Background: Findings in the literature have been quite conflicting with respect to predicting residual pleural thickening (RPT) for tuberculous pleurisy (TP). The aim of this study was to determine which sonographic feature of TP might help in predicting the development of RPT.

Methods: Eighty-seven patients with TP were enrolled prospectively. The initial sonographic features were classified as anechoic, homogenously echogenic, complex non-septated, and complex septated. RPT level was measured 12 months after the start of anti-TB treatment. Spirometry was performed at the 6th and 12th months after the start of anti-TB treatment.

Results: A higher odds of RPT level > 10 mm was found in patients with positive TB bacillus culture in pleural fluid (OR, 20.9; 95% CI, 2.2-198.0) and complex septated sonographic pattern (OR, 145.0; 95% CI, 22.3-942.3). Complex septated sonographic pattern can predict RPT with a sensitivity of 80%, specificity of 96%, positive predict value of 84%, and negative predict value of 94%. Patients with RPT level > 10 mm had a lower force vital capacity than those without (75.4 ± 9.2 % predicted vs. 83.2 ±9.5 % predicted, p < 0.01)

Conclusion: Complex septated sonographic pattern is a useful sign to predict RPT level > 10 mm one year after the start of anti-TB treatment. RPT level > 10 mm is associated with a high probability of decreased lung volumes. Therefore, the initial sonographic feature is beneficial in predicting the sequelae of TP after treatment.