Name of the Procedure:

Technetium Tc-99m Macroaggregated Albumin (Tc-99m MAA) Scintigraphy, also known as a Lung Perfusion Scan or V/Q Scan.

Summary

A Technetium Tc-99m MAA Scintigraphy is a type of nuclear medicine scan used to diagnose and evaluate blood flow in the lungs. It involves injecting a radioactive substance, Technetium Tc-99m MAA, into the bloodstream, which then travels to the lungs. Special cameras capture the distribution of the radioactive particles, creating detailed images for medical assessment.

Purpose

The procedure is primarily used to assess lung conditions such as pulmonary embolism (a blood clot in the lungs), evaluate lung function before surgery, or map blood flow to the lungs. The goal is to provide a clear picture of lung perfusion (blood flow) to aid in accurate diagnosis and treatment planning.

Indications

• Symptoms of pulmonary embolism, such as sudden shortness of breath or chest pain.
• Pre-operative evaluation for lung surgery.
• Assessment of lung function in conditions such as chronic obstructive pulmonary disease (COPD) or other pulmonary vascular disorders.

Preparation

• The patient may be asked to fast for a few hours before the scan.
• Blood tests or other diagnostic assessments might be required.
• Inform the doctor of any medications being taken or allergies, particularly to radioactive materials or contrast agents.

Procedure Description

1. The patient is positioned on a scanning table.
2. A small amount (up to 10 millicuries) of Technetium Tc-99m MAA is injected into a vein.
3. The patient remains still while a special gamma camera takes images of the lungs, capturing the distribution of the radioisotope.
4. The procedure is generally non-invasive and painless.

Duration

The entire procedure usually takes about 30-60 minutes.

Setting

The procedure is typically performed in a hospital radiology or nuclear medicine department or an outpatient imaging center.

Personnel

• Nuclear Medicine Technologist: Administers the radioactive material and operates the gamma camera.
• Radiologist or Nuclear Medicine Physician: Interprets the scan results.
• Nurse: May assist with patient preparation and care.

Risks and Complications

• Mild discomfort at the injection site.
• Rare allergic reaction to the radioactive tracer.
• Exposure to a small amount of radiation, which is generally considered safe.

Benefits

• Provides detailed images of lung perfusion, aiding in accurate diagnosis.
• Non-invasive with minimal discomfort.
• Helps in planning treatments or surgeries with a better understanding of lung function.

Recovery

• No significant recovery time is required.
• The patient can usually resume normal activities immediately after the scan.
• Drink plenty of fluids to help flush the radioactive tracer from the body.
• Follow-up appointments may be scheduled to discuss results.

Alternatives

• CT Pulmonary Angiography: Offers high-resolution images but involves higher radiation doses and potential use of iodinated contrast agents.
• Magnetic Resonance Imaging (MRI): Non-radiative but less commonly used for assessing pulmonary perfusion.
• Doppler Ultrasound: Mainly used for evaluating blood flow in other parts of the body.

Patient Experience

• During the procedure, the patient will need to lie still and may feel a brief pinch at the injection site.
• Post-procedure discomfort is minimal, with no significant pain expected.
• Comfort measures include a warm blanket and reassurance throughout the scan.