DMSA Scan

There are no contraindications to DMSA scan. However, healthcare providers tend to avoid this test in the following conditions:

• Pregnancy
• Breastfeeding 
• Recent or current kidney infection
• Other recent nuclear medicine scans, such as a bone scan

Your healthcare practitioner may order this test in the following situations:

• To check the size, shape, function and position of your kidneys
• To look for evidence of kidney damage (scars) from infection. The symptoms of kidney infection are:
  • Fever
  • Bad-smelling urine 
  • Chills 
  • Pain in the abdomen, side or back
  • Trouble urinating
  • Pain while urinating 
  • Frequent urination 
  • Sudden urge to urinate 
  • Nausea and vomiting 
  • Fatigue
  • To estimate the function of kidneys before planning a surgery or for targeted radiation treatment

You do not need special preparation before the DMSA scan and can continue with your normal diet and medications.

However, your doctor may ask you to stay hydrated for the test. Tell your doctor if you are breastfeeding or think you may be pregnant. Also, inform him/her if you are allergic to medicines or the contrast dye.

The radioactive medicine is injected three to four hours before the test.

The doctor may give sedatives, especially to children who cannot sit still. On the day of the test, make sure to wear clothes that do not have metal objects like buttons or zips.

The following procedure is performed for the DMSA scan:

• Your doctor will inject the DMSA into a vein in your arm using a needle or a small plastic tube called a cannula. A numbing spray or cream may be put on the skin before inserting the needle or cannula.
• After three to four hours of injecting the chemical, the doctor will ask you to empty your bladder.
• He/she will then ask you to lie on the scan table and will position a large camera above you.
• The camera may stay in one place or move slowly around you as the images are captured.
• Make sure to remain still during the scan to prevent blurring of the images.

DMSA scan takes nearly 15 to 20 minutes.

You may feel some discomfort with the insertion of the needle into the vein. The site of injection may feel a little sore for a while after the test.

The following conditions can be assessed using a DMSA scan:

• Kidney infection
• Birth defects in the kidneys, such as:
  • Kidneys fused at the base to form a horseshoe shape (horseshoe kidney)
  • Abnormal location of one or both kidneys (renal ectopia)
  • Multiple fluid-filled sacs in the kidneys (multicystic dysplastic kidneys)
• Acute kidney failure
• Damage or death of kidney tissue due to loss of blood supply (renal infarction)
• High blood pressure caused by reduced blood supply to the kidneys
• Trauma to the kidneys

Benefits:

• The test can assess and compare the function of both kidneys.

Risks:

• There is a possible risk of allergic reaction to the radioactive material.
• There is a slight risk of harmful effects of radiations to the unborn baby during pregnancy.
• The amount of radioactive material used for the scan is very small - almost equal to four months of background radiation (radiation present in the environment). It becomes inactive in a few hours and is eliminated through the urine or faeces.

You can leave soon after the test and resume normal activities. However, if you were given sedatives, your doctor may keep you under observation for a while.

Your body will eliminate DMSA during the first 24 hours after the test. During this period, you must:

• Drink plenty of water.
• Flush the toilet well and wash your hands properly each time you use the toilet. 
• Avoid close contact with pregnant women.

A SPECT/CT (single-photon emission computed tomography) scan may be performed along with the DMSA scan.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.