A DMSA (Dimercaptosuccinic Acid) scan procedure, used to assess kidney scarring and function, involves two main phases: an initial injection and delayed imaging. While the actual scanning part typically takes 30 to 60 minutes, the entire process, from injection to imaging, can extend over several hours, as the imaging is usually performed 2 to 4 hours after the radioactive tracer is administered.
Differentiating DMSA and DTPA Renal Scans
It's important to distinguish between different types of renal scans, as their procedures and durations can vary. For instance, a Renal DTPA (Diethylene Triamine Pentaacetic Acid) scan, which primarily evaluates blood flow to the kidneys and urine drainage, follows a different timeline. The active imaging process for a Renal DTPA scan usually takes 30 to 45 minutes.
The procedure for a DTPA scan typically begins with the patient being asked to clear their bladder. Following this, the clinician will measure the patient's blood pressure and insert an intravenous (IV) line into a superficial vein in the arm to administer the radiotracer. This contrasts with the DMSA scan's delayed imaging approach.
What to Expect During a DMSA Scan
Preparing for a DMSA scan is generally straightforward, often requiring no specific dietary restrictions, though hydration might be recommended. Here’s a general overview of the process:
- Injection Phase: A small amount of radioactive tracer (DMSA) is injected into a vein, usually in the arm. This tracer travels to the kidneys.
- Waiting Period: There is a waiting period, typically 2 to 4 hours, to allow the DMSA to be absorbed by the kidney tissue. During this time, you might be allowed to leave the imaging department or wait in a designated area.
- Imaging Phase: You will lie on a scanning table while a special camera (gamma camera) takes images of your kidneys. This part of the scan is non-invasive and painless. You may be asked to hold still or change positions slightly to get clear images.
- Duration: The actual imaging session itself usually lasts between 30 to 60 minutes.
| Scan Type | Primary Purpose | Typical Imaging Duration | Overall Process Time (Injection to Completion) |
|---|---|---|---|
| DMSA Scan | Kidney function, scarring, anatomy | 30-60 minutes | Several hours (due to delayed imaging) |
| DTPA Scan | Kidney blood flow, urine drainage | 30-45 minutes | 30-45 minutes (dynamic imaging) |
Why Are Renal Scans Performed?
Renal scans, including DMSA and DTPA, are valuable diagnostic tools used to assess various kidney conditions. They provide detailed information about:
- Kidney size, shape, and position.
- Presence of kidney scarring, often due to recurrent urinary tract infections (UTIs).
- Blood flow to the kidneys.
- How well the kidneys are draining urine and identifying any obstructions.
- Assessment of kidney function in various kidney diseases.
For more detailed information on specific procedures and what to expect, consulting with your healthcare provider or visiting reputable medical websites like Mayo Clinic is recommended.
