Pericardial Effusion CT Imaging Characteristics

CT scanning is highly sensitive for the detection of pericardial effusion, capable of identifying even small amounts of fluid accumulation. In contrast, conventional X-ray imaging typically requires moderate to large volumes of fluid before changes in cardiac silhouette become apparent.

Causes of Pericardial Effusion

Pericardial effusion can arise from a variety of underlying conditions, including pyogenic infections, rheumatic diseases, tuberculosis, and metastatic cancer. Each of these etiologies may present differently clinically, but they share a common radiological appearance on CT scans.

CT Imaging Features

Regardless of the cause, pericardial effusion appears on CT as a fluid-density shadow along the surface of the pericardium. The thickness of this fluid layer helps classify the severity of the effusion: a width of 5 to 15 mm is considered a small effusion, 15 to 25 mm is classified as moderate, and anything above 25 mm is regarded as a large effusion.

Enhancement Patterns

After contrast administration, the pericardium typically enhances significantly, while the fluid itself does not enhance. This contrast difference makes the effusion more clearly visible, aiding in accurate diagnosis and measurement.