Which imaging modalities are recommended for the diagnosis and assessment of empyema in primary care settings?

In primary care settings, the initial recommended imaging modality for the diagnosis and assessment of empyema is a chest X-ray, which can identify pleural effusions and suggest the presence of empyema through characteristic findings such as fluid layering or loculations. If further assessment is required or if the diagnosis remains uncertain, referral for advanced imaging such as ultrasound or computed tomography (CT) of the thorax is advised. Ultrasound is particularly useful for detecting pleural fluid, guiding thoracentesis, and differentiating empyema from other pleural pathologies. CT thorax provides detailed anatomical information, helps delineate the extent of pleural involvement, and can identify loculated collections or underlying lung pathology. Magnetic resonance imaging (MRI) is less commonly used in primary care but may be considered in complex cases or when CT is contraindicated. These recommendations align with UK clinical guidelines emphasizing chest X-ray as the first-line imaging and the use of ultrasound and CT for further evaluation, supported by literature highlighting the complementary roles of ultrasound and CT in pleural disease assessment (McLoud, 1998; Domej et al., 2003; Qureshi and Gleeson, 2006) ¹.