Strontium-82/rubidium-82 generators

Rubidium-82 chloride is a potassium analogue used for PET myocardial perfusion imaging: its uptake into myocardium is proportional to blood flow via active Na+/K+-ATPase transport, with a single-capillary extraction fraction above 50%. Because 82Rb's physical half-life is only about 75 seconds, it cannot be shipped and must be produced at the point of use from its parent strontium-82 (half-life about 25-26 days), which is itself accelerator-produced by proton bombardment of a rubidium target and shipped to hospitals loaded on a generator column (commonly a hydrous stannic (tin) oxide matrix, 90-150 mCi/3.3-5.6 GBq of 82Sr at calibration). Elution with additive-free 0.9% saline yields rubidium-82 chloride injection; the very short daughter half-life allows the column to be re-eluted roughly every 10 minutes, supporting rapid sequential rest/stress imaging of many patients per day.

Commercial systems (Bracco's CardioGen-82, approved in the US in 1989, and the newer Jubilant DraxImage RUBY-FILL) are used with dedicated infusion systems; the FDA label specifies adult rest/stress doses of 1,110-2,220 MBq (30-60 mCi) per component, imaging started 60-120 seconds after infusion, and mandatory testing of strontium-82 and strontium-85 breakthrough in the eluate. A generator remains usable for about 28-42 days depending on loaded activity. Comparative studies have found RUBY-FILL's 82Rb production efficiency roughly 7% higher than CardioGen-82's over a generator's working life, with both requiring daily quality assurance for breakthrough and elution accuracy.