PURPOSE: To establish the value of chest radiograph with regards to the recognition and quantification of pleural effusion and to establish the minimum amount of fluid necessary to produce the radiographic signs of effusion in children.
METHODS: Chest radiographs of twenty-six patients aged 6–18 years with pleural effusion admitted at the University of Santo Tomas Hospital from January 2002-June 2007 were reviewed and compared with ultrasonographic findings as to the presence of effusion and quantity of pleural fluid.
RESULTS: Pleural effusion was correctly identified by chest radiograph in 24 subjects (92%). Two (8%) showed pleural effusion in chest radiograph but negative in ultrasound. Overall sensitivity was 100% with a positive predictive value of 92%. Specificity and negative predictive value was 0% with a positive likelihood ratio of 1. Consolidation was the most common accompanying lesion noted and the most common lesion mistaken for effusion. Based on the Fisher exact test (0.6759), there is no significant relationship between accompanying lesions and fluid level. Using chi-square test, there is a relationship between fluid level on chest radiograph and fluid volume on ultrasound.
CONCLUSION: Chest radiograph is highly sensitive but non-specific in recognizing pleural fluid. Therefore, chest x-ray does not have a good diagnostic value to test for the identification of pleural effusion. Pleural fluid volume as small as 20 mL is enough to produce radiologic changes in children.
CLINICAL IMPLICATIONS: Studies on pleural effusion in children is lacking and further studies in this field is warranted so as to avoid using adult standards for children.
DISCLOSURE: Galilee Giron-Ramos, No Financial Disclosure Information; No Product/Research Disclosure Information