CT of the Pericardium
The pericardium is a double walled sac which covers the heart and the origin of the large vessels which arise from it. The pericardium helps keep the heart in place. A small amount of fluid in the sac reduces friction between the beating heart and adjacent structures. The normal pericardium can be seen as a thin covering over the heart.
Pericardial Fluid
The most common abnormality of the pericardium is fluid build up in the sac called a pericardial effusion. Fluid accumulation can impair heart function and prevent filling of the chambers with blood in some cases. This can lead to a condition called tamponade in severe cases which can be life threatening. We can see the fluid well on CT scan of the chest.
The most common causes of pericardial effusion include inflammatory conditions such as lupus or rheumatoid arthritis. Various viral and bacterial infections can cause fluid build up around the heart. Kidney failure, cancer, and after heart attack are some of the other causes of fluid around the heart.
Inflammation of the pericardium
Pericarditis is an inflammation of the pericardium. Diagnostic criteria involve EKG abnormalities, chest pain, abnormal labs indicating inflammation, and Imaging tests showing inflammation and fluid. Pericarditis can occur from many conditions including infections, following injury from heart attack or trauma, systemic inflammatory conditions like lupus, medications in addition to others. On CT, the pericardium will look thickened.
Air around the heart
Pneumopericardium or gas in the sac surrounding the heart has many causes. Prior surgery, penetrating trauma, infection, and an abnormal communication with the stomach or bowel can lead to gas being present in the pericardium. The gas in some cases can impair heart function and be life threatening. Gas is well seen in the pericardium on CT.
Cysts and masses
Cysts and Masses can involve the pericardium. Cysts are usually benign asymptomatic abnormalities and well seen on CT. All types of solid tumors can involve the pericardium. The most common is spread of cancer from somewhere else in the body like breast or lung cancer. Primary tumors can also occur in the pericardium but are rare and often need tissue sampling for diagnosis.
Failure of development of the pericardium
Another rare condition is called pericardial agenesis or lack of development of the pericardium. This is a condition your born with. It can be a partial or complete defect. It is usually asymptomatic but can sometimes impair heart function and be life threatening. CT may show non visualization of the pericardium and excessive leftward positioning of the heart.
Pericardial abnormalities are well seen on CT scans. Additional imaging can be done with ultrasound or echocardiograms and MRI. Pericardial abnormalities can be life threatening due to impairment of heart function in some cases. Pericardial abnormalities therefore need prompt diagnosis and treatment.