Rubidium-82

Rubidium-82

Rubidium-82 decay scheme

Rubidium-82 is a radioactive isotope of the chemical element rubidium, which is used in positron emission tomography (PET) imaging. It is particularly useful in cardiac imaging to assess myocardial perfusion.

Properties

Rubidium-82 has a half-life of approximately 1.273 minutes, making it a short-lived isotope. It decays by beta plus decay (positron emission) to stable krypton-82. The decay process involves the emission of a positron, which subsequently annihilates with an electron, producing two gamma photons that are detected in PET imaging.

Production

Rubidium-82 is typically produced in a strontium-82/rubidium-82 generator. Strontium-82, which has a longer half-life of 25.36 days, decays to rubidium-82. The generator system allows for the continuous elution of rubidium-82, providing a convenient source of the isotope for clinical use.

Medical Applications

Rubidium-82 is primarily used in myocardial perfusion imaging to evaluate blood flow to the heart muscle. This is particularly important in diagnosing and managing coronary artery disease. The short half-life of rubidium-82 allows for rapid imaging, which is beneficial in a clinical setting.

In a typical procedure, rubidium-82 is administered intravenously, and the patient undergoes a PET scan. The distribution of the isotope in the heart muscle is indicative of blood flow, with areas of reduced uptake suggesting potential blockages or reduced perfusion.

Advantages

The use of rubidium-82 in PET imaging offers several advantages:

• Rapid Imaging: The short half-life allows for quick imaging sessions, reducing the time patients need to spend in the scanner.
• High Resolution: PET imaging with rubidium-82 provides high-resolution images, which are crucial for accurate diagnosis.
• Non-Invasive: The procedure is non-invasive, making it safer and more comfortable for patients compared to other diagnostic methods.

Limitations

Despite its advantages, rubidium-82 has some limitations:

• Short Half-Life: While beneficial for rapid imaging, the short half-life requires on-site production or a nearby generator, limiting its availability.
• Cost: The production and maintenance of a strontium-82/rubidium-82 generator can be costly.

File:PETcomaprison.jpg

Comparison of PET imaging techniques

Related Pages

• Positron emission tomography
• Myocardial perfusion imaging
• Strontium-82
• Coronary artery disease