Technetium-99m-labeled albumin microsphere (Tc-99m-albumin microsphere)

Technetium-99m-labeled albumin microspheres are diagnostic nuclear medicine agents created by aggregating human serum albumin and labeling it with technetium-99m, a gamma-emitting radionuclide. When injected into systemic or organ-specific vasculature (such as hepatic or pulmonary arteries), these microspheres become localized within the microvasculature, where they emit gamma photons that can be detected by gamma cameras, enabling perfusion mapping and the assessment of vascular function. This agent is primarily used in diagnostic imaging procedures like lung perfusion scans, preoperative vascular mapping for surgery, planning for selective internal radiation therapy, and evaluation of tumor vasculature for radioembolization. They are not biological therapeutic targets, but rather marker particles for imaging, with safety concerns focused on non-target embolization and minimal radiation exposure.

Other names

Technetium-99m Macroaggregated Albumin (Tc-99m MAA)Tc-99m-labeled albumin microsphereTc-99m albumin microspheres