Pericardial effusion: Meaning in a Radiology Report

Pericardial effusion

Also written as: pericardial fluid

A pericardial effusion is extra fluid in the sac around the heart. Small amounts are common and often harmless.

Seen on: CT, Ultrasound, MRI

How it reads in a report

Small pericardial effusion measuring up to 7 mm in thickness, without CT signs of tamponade.

What it means

The heart sits inside a thin, two-layered sac called the pericardium. A small amount of fluid between the layers lets the heart move smoothly as it beats. An effusion means more fluid than normal has built up. On ultrasound it shows as a dark rim around the heart. On CT or MRI it appears as a band of fluid surrounding the heart.

When it matters

Small effusions are common and often cause no trouble. They can come with a recent viral illness, inflammation of the sac (pericarditis), kidney failure, an underactive thyroid or recent heart surgery. A large effusion, or one that builds up quickly, can press on the heart and stop it filling properly. This is called tamponade and is an emergency. A heart ultrasound (echocardiogram) is often used to follow an effusion.

Questions to ask your doctor

How large is the pericardial effusion, and is it new?
Is there any sign that the fluid is pressing on my heart?
Do I need an echocardiogram to check it again, and when?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.