(Fig. 2.2)
Normal renal ultrasound: it shows longitudinal scan through the right
kidney demonstrating the relationship to the right lobe of the liver
anteriorly and the paraspinal muscle posteriorly. The kidney shows
echogenecity less than that of the adjacent liver
(Fig. 2.3a)
It shows a well-circumscribed right upper polar cyst (c) with a
sonolucent "echo-free" pattern, thin wall, well-defined posterior margin
and posterior echo-enhancement (due to good transmission of the
ultrasound waves through the fluid content).