It is important to check the function of kidneys often. Kidney disease is known as a "silent killer" because it can progress without noticeable symptoms. One method to test kidney function is Lasix renogram, a simple procedure. The test does require exposure to a small amount of radiation. The amount of exposure is the equivalent of an X-ray.
The procedure begins with an injection of a tracer into the bloodstream at the arm. The tracer is a radioactive substance; however, the amount is minimal and does not have harmful effects. This injection is in most cases followed by an injection of Lasix, a diuretic. The travel of the flow through the kidneys is then measured through pictures taken from a gamma camera by a radiologist.
Images are taken at three minute intervals. After the images are taken a computer plots them on a time graph with each kidney tracked separately. This is how the radiologist tracks the flow through the kidney.
The purpose of this test is to trace blood flow through the kidney. Its secondary purpose is to see how long it takes urine to pass out of the body. The Lasix is used to stimulate urine flow as the tracer is followed via the camera.
Because the examination involves exposure to radiation, it is important to inform the doctor if you are pregnant or breastfeeding. Also, one hour before the test you must drink at least two 8-ounce glasses of water.
The entire procedure takes one hour minimum. The injection of the tracer is given and then you must have photos taken for up to 45 minutes. After the images are examined by a radiologist, they then share the results with you. The tracer passes through the body completely in 24 hours.