The role of chest radiography in diagnosing patients with tuberculous pericarditis
Aim: To describe the abnormalities on chest X-ray (CXR) in patients presenting with tuberculous pericardial effusions. Methods: One hundred and seventy patients presented to Tygerberg Hospital with large pericardial effusions (epi-pericardial separation > 10 mm). All patients had a diagnostic work-up, which included CXR, ECG, two-dimensional echocardiography and HIV serology. Echocardiography was followed by pericardiocentesis and drainage. Pericardial fluid was analysed for adenosine deaminase (ADA), Ziehl Neelsen (ZN) stain, bacterial and mycobacterial cultures. Sputum was sent for ZN stain and mycobacterial cultures. Tuberculous pericardial effusions were diagnosed according to predetermined criteria. Results: The diagnosis of tuberculous pericarditis was made in 53% (n = 90) of patients with pericardial effusions. Forty-one of the subjects (45.5%) were HIV positive. All patients had an enlarged cardiac silhouette and in the majority of cases, the cardiac shadow was globular with distinct margins. The cardiothoracic ratio (CTR) exceeded 0.55 in all patients. The amount of fluid drained correlated with the radiographic finding of cardiac enlargement. Conclusion: In developing countries where TB is very prevalent, CXR plays an important role in the identification of large pericardial effusions. Although sonography will still be required for a definite diagnosis, the results of this study show that CXR is a useful screening tool.