Technetium (99mTc) albumin aggregated

A radiopharmaceutical used in medical imaging

Technetium (99mTc) albumin aggregated
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INN
Drug class
Routes of administration	Intravenous
Pregnancy category
Bioavailability
Metabolism
Elimination half-life	6 hours (for 99mTc)
Excretion
Legal status
CAS Number	76522-21-9
PubChem	119538
DrugBank	DB09143
ChemSpider	106679
KEGG	D06199

Technetium (99mTc) albumin aggregated is a radiopharmaceutical used primarily in nuclear medicine for lung perfusion scans. It is a compound of technetium-99m (99mTc), a metastable nuclear isomer used in various diagnostic imaging procedures, and human serum albumin that has been aggregated to form small particles.

Mechanism of Action

Technetium (99mTc) albumin aggregated works by being injected intravenously into the patient, where it travels through the bloodstream and becomes trapped in the capillaries of the lungs. The aggregated albumin particles are of a size that allows them to become lodged in the pulmonary capillaries, providing a map of blood flow in the lungs. The 99mTc emits gamma rays, which can be detected by a gamma camera, allowing for the visualization of lung perfusion.

Clinical Use

This radiopharmaceutical is primarily used in ventilation/perfusion scans (V/Q scans) to evaluate pulmonary embolism, a condition where one or more arteries in the lungs become blocked by a blood clot. The V/Q scan involves two parts: a ventilation scan to assess air flow and a perfusion scan to assess blood flow. Technetium (99mTc) albumin aggregated is used in the perfusion part of the scan.

Preparation and Administration

The preparation of technetium (99mTc) albumin aggregated involves the reduction of pertechnetate (99mTcO4-) with a stannous agent in the presence of human serum albumin. The resulting aggregated particles are then suspended in a saline solution for intravenous injection. The typical dose for a lung perfusion scan is 1-4 mCi (millicuries).

Safety and Side Effects

Technetium (99mTc) albumin aggregated is generally safe when used as directed. However, as with any radiopharmaceutical, there is a small risk of radiation exposure. Side effects are rare but may include allergic reactions, such as rash or itching. It is important to assess the patient's history for any known allergies to albumin or other components of the preparation.

Also see

• Technetium-99m
• Radiopharmaceutical
• Nuclear medicine
• Lung perfusion scan
• Ventilation/perfusion scan