Lipomas are the most common type of benign (non-cancerous) fat-containing masses and demonstrate a characteristic appearance on MRI. The cause is not fully understood, but there is a genetic factor as they typically run in families. Usually these tumors do not cause symptoms, but can become painful if large and pressing on nearby nerves.

Hemangiomas are benign (non-cancerous) growths that develop from blood vessels. Hemangiomas of the skin are often visible as red, raised birthmarks that generally fade on their own; hemangiomas can also form on internal organs. Most hemangiomas cause no symptoms, but for those that do, symptoms (i.e. pain, numbness) vary depending on the size and location of the tumor.

Vascular malformation is a general term to describe when blood vessels and/or lymph vessels have an abnormal appearance or connection because of developmental variation - this is a rare but benign (non-cancerous) finding. One type of vascular malformation is an arteriovenous malformation (AVM), which is when the artery and vein are directly connected, instead of being connected by small capillaries.

Hemangiomas are common, generally benign (non-cancerous), abnormal collections of blood vessels in the liver that usually do not require treatment. The cause of hemangiomas is unknown. Occasionally, larger hemangiomas (greater than 5 cm) can cause symptoms such as progressive right upper abdominal pain.

The liver contains bile ducts which carry bile, a fluid that helps the digestion of fats, into the intestines. Liver hamartomas are dilated cystic bile ducts. It is usually asymptomatic (does not cause symptoms) and benign (non-cancerous),

Small liver cysts are pockets of fluid and usually cause no signs or symptoms and need no treatment. Liver cysts that are not causing symptoms and are found incidentally (unintentional finding when looking for something else) are usually not at risk of becoming malignant (cancerous).

Masses are growths in the liver. They could be harmless and benign or something more significant such as cancer (e.g. hepatocellular carcinoma).

Liver metastases are lesions seen in the liver caused by the spread of cancer from other organs to the liver.

A granuloma (a non-cancerous lesion that contains small abnormal clumps of cells) forms as a result of an inflammatory reaction in body tissues. Granulomas that are found in the liver are associated with inflammation caused by infection (e.g. mycobacterial infection), liver disorders (e.g. primary biliary cholangitis), and noninfectious causes (e.g. sarcoidosis, medication-induced liver injury).

Sometimes there is a finding in an organ that is found in passing and is too small to get a clear view from the scan images. This makes it difficult to provide a diagnosis of the finding. There is an incompletely characterized lesion of the kidney. Usually, this finding is a cyst (pocket of fluid) - a common, benign (non-cancerous) finding.