Cardiac Rubidium-82 PET
Myocardial perfusion imaging with Rb-82 — a generator-produced positron emitter (parent Sr-82, ~25-day half-life in generator). Rest and pharmacologic-stress (regadenoson, dipyridamole) acquisitions with quantitative myocardial blood flow and coronary flow reserve. Higher accuracy and lower radiation than SPECT MPI, but limited to centers with PET / CT and on-site Rb-82 generator access.
Clinical pathway
- Rest imaging — 30–40 mCi Rb-82 IV, ~6-minute gated list-mode acquisition.
- Pharmacologic stress — regadenoson 0.4 mg IV; peak vasodilation at ~2 min.
- Stress imaging — repeat Rb-82, ~6-minute acquisition.
- Quantitative analysis — absolute myocardial blood flow (mL/g/min) and coronary flow reserve.
- Reporting — perfusion defects, transient ischemic dilation, reduced CFR, balanced ischemia detection.
Typical systems
- GE Discovery IQ
- GE Discovery MI
- GE Discovery 690
- Siemens Biograph mCT
- Siemens Biograph Vision
- Philips Vereos
- Philips Gemini TF
Requires Rb-82 generator (Bracco CardioGen-82, Jubilant RUBY-FILL) and infusion system on-site.
Room + procedure characteristics
- Total visit: 30–45 min (vs 3+ hours for SPECT MPI).
- Dose: ~3–4 mSv (vs ~10 mSv for Tc-99m sestamibi SPECT).
- Team: nuclear cardiologist or nuclear radiologist + NM tech + stress-test RN.
Equipment considerations that bite
- List-mode acquisition is required. Cardiac Rb-82 protocols depend on dynamic list-mode reconstruction for absolute MBF; a PET / CT without list-mode is not a cardiac PET tool.
- ToF timing performance — ToF reduces image noise on the short Rb-82 acquisition. SiPM-era systems (Vision, Discovery MI, Vereos) outperform PMT-era systems on quantitation precision.
- Quantitative MBF software — Corridor4DM, syngo MBF, FlowQuant, MunichHeart. A scanner without modern MBF analysis software runs cardiac PET as a perfusion-only test, missing the quantitative differentiator.
- Generator infrastructure — generator weight (~80 lb), shielded cart, dedicated infusion line, water-quality discipline. Site planning for the generator cart is non-trivial and frequently underestimated.
- CT side — attenuation-correction CT minimum; respiratory motion correction matters at low heart rates and bariatric body habitus.
Regulatory + supply chain reality
- Generator supply — Sr-82 production is a small-set manufacturer chain; a missed generator delivery means cancelled cases that day. No on-site fallback exists.
- NRC / Agreement-State authorized-user credentialing for cardiac PET is the gating personnel constraint. NRC license, RSO, dose calibrator daily QC.
- Reimbursement — quantitative MBF may or may not be separately reimbursed depending on payer and jurisdiction. Program economics depend on it.
Operational reality
- Cardiac Rb-82 PET is a program, not a scan. Generator contract, MBF software, infusion pump, stress-RN coverage, and quantitative-reporting workflow all have to be in place before the first patient.
- Throughput — generator elution cycles are short, so back-to-back-cases workflow is feasible if stress lab and uptake-room layout support it. The infusion / stress / acquisition sequence is highly choreographed.
- Volume growth is driven by referring cardiology comfort with quantitative MBF; program adoption follows a learning-curve, not a marketing pattern.