Produced from a Sr-82/Rb-82 generator (strontium cow) — the generator is leased and connected directly to an infusion system at the scanner, requiring no on-site cyclotron. This makes Rb-82 the most widely available PET myocardial perfusion agent.
Acts as a potassium analogue — taken up by viable myocardium via Na/K-ATPase in proportion to blood flow, similar to Tl-201 but imaged with PET.
Advantages over SPECT MPI (sestamibi/tetrofosmin):
- Higher sensitivity and specificity for CAD detection
- Absolute myocardial flow quantification (mL/min/g) and flow reserve — identifies balanced ischemia (3-vessel disease) that SPECT misses
- Faster study (total ~45 min vs 3–4 hours for SPECT)
- Lower radiation dose
Limitation: 75-second half-life means the patient must be positioned on the scanner prior to injection, and pharmacologic stress (adenosine, regadenoson, dipyridamole) must be used — exercise stress is not feasible given the rapid decay.
Rb-82 vs N-13 ammonia vs F-18 flurpiridaz: Rb-82 is generator-based (no cyclotron); N-13 ammonia requires on-site cyclotron (11-min t½); flurpiridaz (F-18, 110-min t½) can be centrally produced and shipped, improving access.