Full head-to-head comparison of ultrasonography and CT scan in volumetric quantification of pleural effusion: a systematic review and meta-analysis.

Pleural effusion is a very common clinical finding. Quantifying pleural effusion volume and its response to treatment over time has become increasingly important for clinicians, which is currently performed via computed tomography (CT) or drainage. To determine and compare ultrasonography (US), CT, and drainage agreements in pleural effusion volumetry. Protocol pre-registration was performed a priori at ( https://osf.io/rnugd/ ). We searched PubMed, Web of Science, Embase, and Cochrane Library for studies up to January 7, 2024. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2), QUADAS-C, and Consensus-based Standards for the selection of health Measurement Instruments (COSMIN). Volumetric performances of CT, US, and drainage in assessment of pleural effusion volume were evaluated through both aggregated data (AD) and individual participant data (IPD) analyses. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Six studies were included with 446 pleural effusion lesions. AD results showed a perfect level of agreement with pooled Pearson correlation and intraclass correlation coefficient (ICC) of 0.933 and 0.948 between US and CT. IPD results demonstrated a high level of agreement between US and CT, with Finn's coefficient, ICC, concordance correlation coefficient (CCC), and Pearson correlation coefficient values of 0.856, 0.855, 0.854, and 0.860, respectively. Also, both results showed an overall perfect level of agreement between US and drainage. As for comparing the three combinations, US vs. CT and US vs. drainage were both superior to CT vs. drainage, suggesting the US is a good option for pleural effusion volumetric assessment. Ultrasound provides a highly reliable, to-the-point, cost-effective, and noninvasive method for the assessment of pleural effusion volume and is a great alternative to CT or drainage.