The echogenicity of the kidneys on ultrasound examination is usually a judgement call on the part of the radiologist who is interpreting the study. It is usually based on a comparison to the echo density of the liver or the spleen. In some cases this may be significant and in other cases, it may not be significant. I suggest that you consult with your physician for his or her opinion of the study.
For additional information about tests to measure kidney function, please visit: https://www.kidney.org/atoz/content/kidneytests