Kidney Quest: The Final Sonogram and the MRI

Once blood tests have been completed, two additional tests remain: an ultrasound of the kidneys and an MRI.

an image of kidneys from an MRI

Most people today have had ultrasounds. The most difficult part of this test is the cold jelly. Like stethoscopes, I believe the jelly is stored in the freezer before use. But the ultrasound test is surprisingly comforting. The cool gel relaxes. The tech kept the lights dim, and the slow rotation of the trandsducer probe--the probe that sends the sound waves to the computer, felt like a soft massage--a belly rub which lasts about fifteen minutes.

The ultrasound checks the health of the kidneys, but a more detailed test must follow. This is the MRI or magnetic resonance imaging. This will test, in depth, the blood vessels and the kidney.

An MRI representation

How the MRI Works:

1. You are slid into a large open tube so that the kidneys are central to the imaging
2. The MRI can make images along any plane. The CT can only take it alone one plane and then the patient needs to be re-positioned.
3. The magnet in the MIR is one-thousand times stronger than the earth's magnetic field. Thus stethoscopes, paper clips, pens, etc. can be unexpectedly pulled out of pockets and hurled toward the magnetic center.
4. Patients are screened for metallic implants. If a patient had a staple or pin implanted at least six weeks prior, he or she can safely withstand the magnetic field because scar tissue builds up and holds the pin in place.
5. The MRI works with hydrogen atoms.As the magnet of the MRI works, the atoms essentially line up along the magnetic field, with the MRI either pointing toward the patient's head or feet. However, enough don't, and it's from these that we get the image.
6. MRIs have no radiation. The only drawback is for those with claustrophobia. Since can be in the machine for over an hour, the closed space terrifies some people. But today, we have open MRIs--so essentially, no complications from the MRI unless the patient develops an allergy to the dye.