Testing & Diagnosis for Acute Kidney Injury in Children


The first step in treating your child is forming an accurate and complete diagnosis, and in order to minimize damage to your child’s kidneys, it’s important that AKI be diagnosed early. The doctor may order tests including:

1. Blood, urine and other tests to determine how well your child’s kidneys are functioning

There are two main ways to measure your child’s kidney functioning: creatinine level and glomerular filtration rate (GFR).

Creatinine is a waste product that the body makes daily in proportion to a person’s muscle mass. It can leave the body only through the kidneys, and levels can be checked through a simple blood test. If your child has AKI, we will see her creatinine level rise quickly.

GFR (glomerular filtration rate) is a measurement of how efficiently your kidneys are able to filter your blood. Read more about the GFR test at Children’s Hospital Boston.


2. Imaging tests to check for blockages in the urinary tract

These tests might include:

  • abdominal x-ray: invisible electromagnetic energy beams produce images of internal tissues, bones and organs onto film
  • renal ultrasound (also called sonography): a painless, non-invasive test in which a transducer is passed over your child’s kidneys, producing sound waves that bounce off the kidney and transmit a picture on a video screen. The test can detect a mass, kidney stone, cyst or other obstruction or abnormality. Read more about ultrasounds.
  • nuclear medicine study: non-invasive, painless tests that can reveal important information about your child's health. Nuclear medicine uses short-lived radiopharmaceuticals and specialized cameras to create images of the human body. Read more about nuclear medicine studies.

3. Kidney biopsy

This is a procedure in which tissue samples are removed (with a needle or during surgery) from the kidney for examination under a microscope. Read more about biopsies.

After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we’ll meet with you and your family to discuss the results and outline the best treatment options.

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