A common reason for ordering a kidney ultrasound is to see if there are any problems with your kidney function. It is an excellent test modality because it uses high frequency sound waves to bounce off different tissue planes. The probe emits the sound waves and also receives any echoes that return. Dense and solid tissue will cause sound waves to bounce back to the receiver while liquid will not reflect the echoes back to the receiver. The information received is interpreted by the software as white or hyperechoic for dense tissue but black or hypoechoic for liquid mass. It is an excellent screening examination, but it does not give your doctor
intricate details to say what the mass is exactly. Further imaging like an abdominal CT scan
or an MRI is often needed as a confirmatory test.
Simple renal cysts are actually fairly common, especially in the elderly. This is also true for liver cysts. In fact, more than half of people over the age of 50 years will have these cysts. Renal cysts can be simple or complex, small or large. The concern is the possibility of renal cell carcinoma. It is best to discuss this issue with a primary care physician
. Your doctor will order the tests and can help you understand the results in the context of your medical history.