Historically, in marine mammals, ultrasound has been used predominantly for reproductive studies. However other applications including echocardiology, abdominal evaluation and thyroid evaluation are starting to gain recognition. Researchers have also used ultrasound to determine blubber depth.

One of the biggest obstacles when using ultrasound in marine mammals is the thick blubber layer that is highly reflective and attenuating, and the large size of many animals.

Long-finned Pilot Whale Globicephala melas

Below is an ultrasound image of the right side of the liver of an emaciated male pilot whale that stranded in Cape Cod. An image of normal liver is provided underneath for comparison. The abnormal liver is hyperechogenic and hyperattenuating. In small animal medicine this would be  most suggestive of fibrosis, steroid hepatopathy or hepatic lipidosis depending on species, although other hepatopathies could not be completely ruled out without tissue sampling. Histopathology showed that this liver contained large quantities of lipid within the hepatocytes.

Histologically abnormal liver:

Histologically normal liver:

These findings suggest that pilot whales may suffer from hepatic lipidosis similarly to domestic cats, with inappropriate mobilization of fat during periods of anorexia. Little information about this condition in whales is currently available in the literature.