Rubidium (81rb) / Krypton (81mkr)

What it is and how it works

Rubidium-81 (half-life about 4.6 hours) decays to krypton-81m, an inert radioactive gas with a half-life of about 13 seconds that emits gamma radiation suitable for imaging. Eluted from the generator with humidified air or oxygen and inhaled continuously, krypton-81m distributes in proportion to regional ventilation and decays almost immediately, giving a very low radiation dose.

Indications

Lung ventilation scintigraphy, usually combined with perfusion imaging, for the diagnosis of pulmonary embolism and assessment of regional lung function.

Dosage and administration (summary)

Administered by continuous inhalation from the generator during imaging in a nuclear medicine department; the activity used is determined by the imaging protocol.

Contraindications

No specific contraindications are generally recognised; the need for the examination should be considered carefully in pregnancy.

Warnings and precautions

Generator elution and inhalation must be performed by trained staff in accordance with radiation-protection regulations. Because of the short generator shelf life, use must be scheduled within the stated expiry.

Pregnancy

Radiation dose to the fetus is very low, but the examination should be performed only when clearly indicated.

Storage and supply

Store the generator in its shielding at room temperature according to the manufacturer’s instructions and radiation-protection regulations.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.