What kind of tissue can an ultrasound penetrate?

Ultrasound can penetrate most soft tissues, such as muscles, organs, and blood vessels. It is commonly used for medical imaging and diagnostic purposes, such as ultrasound scans of the abdomen, heart, and fetus. Ultrasound waves have difficulty passing through dense tissues like bone, air, and fat. Bone reflects ultrasound waves, which is why ultrasound images of bones often appear as white areas. Air and fat can also interfere with ultrasound waves, which is why ultrasound images of the lungs and gastrointestinal tract can be challenging to obtain.