CT Scans may help distinguish Between Transudates and Exudates in Pleural Effusion: Study

A recent study published in the Respiratory Research found that computed tomography (CT) scans can play an important role in precise distinction between transudative and exudative pleural effusions. Pleural effusion is a common diagnostic challenge in clinical settings and so, this study conducted a comprehensive two-center retrospective analysis analyzed the diagnostic value of thoracic CT scans in this critical differentiation.

The research involved a total of 404 patients from two prominent medical centers, The First Affiliated Hospital of Henan University of Science and Technology (Luoyang cohort) and the First Affiliated Hospital of Zhengzhou University (Zhengzhou cohort). This study focused on individuals who underwent thoracic CT scans followed by diagnostic thoracentesis.

The results from the Luoyang cohort demonstrated that patients with exudative pleural effusions expressed a significantly higher CT values and pleural fluid (PF) to blood CT value ratios when compared to those with transudative effusions. The outcomes determined optimal cut-off points for CT values and PF to blood CT value ratios, achieving impressive accuracy in predicting the nature of pleural effusions.

The CT scan showed an area under the curve (AUC) of 0.85 with a CT value cut-off of 10.81 Hounsfield Units (HU), along with significant sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The PF to blood CT value ratio expressed an AUC of 0.86 with an optimal cut-value of 0.27 by reinforcing its diagnostic utility.

These findings were further validated in the Zhengzhou cohort which confirmed the reliability and effectiveness of CT scans in differentiating between transudates and exudates. The results were promising as they suggest that CT value and PF to blood CT value ratio can serve as reliable indicators in reducing the need for unnecessary thoracentesis procedures.

Reference:

Zhang, Y., Zhang, Y., Wang, W., Feng, X., Guo, J., Chen, B., Zhang, F., Wang, H., Fan, M., Zhu, Y., Sun, Y., Wang, T., Mao, Y., & Gao, P. (2024). Diagnostic accuracy of thoracic CT to differentiate transudative from exudative pleural effusion prior to thoracentesis. In Respiratory Research (Vol. 25, Issue 1). Springer Science and Business Media LLC. https://doi.org/10.1186/s12931-024-02681-w