Choice C is correct. A kidney ultrasound is a noninvasive diagnostic exam used to evaluate the size, shape, and location of the kidneys, as well as blood flow to the kidneys. This imaging modality is particularly useful in detecting abnormalities such as cysts, tumors, obstructions, or other structural anomalies within or around the kidneys.

Choice A is incorrect. A kidney ultrasound does not directly measure electrolyte levels. Instead, it primarily evaluates the structural aspects of the kidneys and blood flow to the kidneys.

Choice B is incorrect. While the kidneys play a role in producing erythropoietin, a kidney ultrasound does not directly evaluate the function of the kidneys in producing red blood cells.

Choice D is incorrect. Urea is a waste product that is removed from the blood by the kidneys, a kidney ultrasound does not directly detect urea levels in the bloodstream.

✓ Renal ultrasound is one of the most commonly performed imaging modalities for evaluating renal anatomy and function. It is estimated that millions of renal ultrasound examinations are conducted annually worldwide.

✓ It may be applicable for the nurse to ensure clients are comfortable during the ultrasound procedure by providing appropriate positioning and support.

✓ Renal ultrasound has a high diagnostic accuracy for detecting renal abnormalities, such as hydronephrosis, renal cysts, tumors, and renal artery stenosis. Studies have reported sensitivity and specificity values exceeding 90% for various renal pathologies.