What Anatomical Structures are Well Seen with US

The solid organs of the abdomen, including the liver, kidneys and spleen, can be evlauated well with US (top image).

Superficial structures (like the thyroid and testicles) can also be evaluated with ultrasound, with production of high resolution images. The bottom right image is of a testicle. The black (anechoic) structure posterior to it (*) is an abnormal collection of fluid around the testicle, called a hydrocele.

Deeper structures can't be seen with the same level of resolution because of the number of scattered, absorbed and reflected sound waves occuring, leaving less sound available to penetrate deeper tissues and reflect back to the transducer. As an example of this, look at the difference in resolution of the upper vs the lower pole of the right kidney. The lower pole is more superifical and is seen with better resolution than the upper pole.