Pericardial cysts

Imaging description Pericardial cysts are congenital lesions that are formed when a portion of the pericardium is pinched off during early development. Pericardial cysts can occur anywhere within the mediastinum, but are most common in the cardiophrenic angles. On CT, pericardial cysts typically have thin to undetectable walls without septation (Figure 64.1). There is no enhancement following contrast administration [1–3] (Figures 64.2 and 64.3). The attenuation of pericardial cysts is usually that of water although rarely they can be higher attenuation. In those cases, MRI is often helpful in determining the fluid nature of the lesion. The cysts usually have low to intermediate signal intensity on T1-weighted imaging although in cases with proteinaceous material in the cyst there may be high signal on T1-weighted imaging. The cysts have homogeneous high signal intensity on T2-weighted imaging [1–3]. Importance Recognition of the fluid attenuation of the pericardial mass allows the exclusion of pericardial or mediastinal neoplasms. Since these are typically asymptomatic, no further workup or treatment is necessary.