Which imaging modality is most commonly used for evaluating pericardial effusion?

Echocardiography is the most commonly used imaging modality for evaluating pericardial effusion due to its availability, real-time imaging capability, and non-invasive nature. This technique utilizes sound waves to create images of the heart and surrounding structures, allowing cardiologists to assess the presence of fluid accumulation in the pericardial space effectively.

In echocardiography, the characteristic appearance of pericardial effusion can be easily identified when observing the heart's movement and the anechoic (dark) space surrounding it. The ability to perform dynamic assessments aids in gauging the size of the effusion and its impact on cardiac function.

While MRI and CT can also visualize pericardial effusions and may provide additional information regarding the nature of the effusion or any associated abnormalities, they are generally not the first-line imaging modalities due to their higher cost, longer acquisition time, and the need for specialized equipment. Nuclear imaging is more commonly used for assessing myocardial perfusion and function rather than structural changes like those seen in pericardial effusion. Thus, echocardiography remains the primary choice in clinical practice for this specific evaluation.