Positron Emission Tomography (PET) myocardial perfusion imaging is one of the most advanced modalities for assessing myocardial blood flow, multivessel coronary artery disease, and microvascular dysfunction. Because PET uses high-cost radiopharmaceuticals, specialized scanners, and multi-phase protocols, coding and billing must be accurate and compliant.
This guide provides a comprehensive breakdown of CPT codes 78429–78431, documentation requirements, stress agent considerations, bundling rules, and payer policies.
Overview of PET Myocardial Perfusion Imaging
PET myocardial perfusion offers several advantages over SPECT:
- Higher spatial resolution
- Accurate quantification of myocardial blood flow (MBF)
- Lower radiation exposure
- Shorter acquisition time
- Ability to differentiate balanced ischemia
- Improved detection of multivessel CAD
Radiopharmaceuticals commonly used include:
- Rubidium-82 (Rb-82) – generator-based
- N-13 Ammonia – cyclotron-produced
- FDG – for viability, but NOT perfusion (different codes)
PET myocardial perfusion studies follow a rest–stress protocol, usually:
- Rest PET perfusion
- Stress PET perfusion (pharmacologic or exercise; mostly pharmacologic)
- Optional blood flow quantification (increasingly required by payers)
CPT Coding for Myocardial Perfusion PET (78429–78431)
CPT 78429 – PET myocardial perfusion imaging, rest only
Used when only a rest perfusion study is performed.
Includes:
- PET acquisition
- Perfusion imaging
- Physician interpretation
- Basic analysis (qualitative)
Documentation must clearly state rest-only imaging and explain why stress imaging was not performed (e.g., unstable angina, contraindication to stress, limited study for viability baseline).
CPT 78430 – PET myocardial perfusion imaging, stress only
Used when only the stress portion is completed.
Requires:
- Documented stress protocol
- Pharmacologic agent details (e.g., regadenoson, adenosine, dobutamine)
- Patient response
- Reason: rest imaging was not performed
Stress-only PET is less common but medically indicated in some pre-operative or follow-up scenarios.
CPT 78431 – PET myocardial perfusion imaging, rest and stress
This is the most commonly billed code for PET myocardial perfusion.
Includes:
- Rest PET perfusion
- Stress PET perfusion
- Physician interpretation of both phases
- Perfusion assessment
- Wall motion & ejection fraction if gated
- Comparison between phases
This code does not include blood flow quantification—that has a separate add-on code (varies by payer and proprietary system).
Blood Flow Quantification – Important Billing Note
Absolute myocardial blood flow (MBF) and myocardial flow reserve (MFR) are essential advantages of PET.
Most systems use Category III codes, such as:
- CPT 0482T – Quantitative cardiac blood flow measurement (PET)
Important considerations:
- Medicare MACs vary: some cover it, some classify it as experimental.
- Commercial payers increasingly require MBF/MFR for ischemia evaluation.
- 0482T is billed in addition to 78431 when quantitative flow analysis is performed.
Documentation for 0482T must include:
- Coronary flow reserve values
- MBF (rest and stress)
- Vessel-specific values (LAD, LCx, RCA)
- Interpretation of clinical significance
What’s Included vs Separately Billable
Included in 78429–78431
- PET acquisition
- Basic attenuation correction
- Reconstruction
- Interpretation of perfusion
- Gated wall motion is performed
- LV ejection fraction
Separately Billable (if medically necessary and documented)
- Radiopharmaceuticals (HCPCS A-codes)
- Stress agents (J-codes)
- Flow quantification (0482T)
- CT for attenuation correction (coverage varies)
- Resting ECG
- IV start/therapeutic injections (if payer-specific criteria are met)
Radiopharmaceutical Billing for PET Perfusion
Rubidium-82 (Rb-82)
Commonly:
- A9555 – Rb-82, 30 mCi
- Bill does units based on payer instructions.
N-13 Ammonia
- A9526 – N-13 ammonia, per study dose
Key considerations:
- Document dose, wastage, lot number, expiration, and NDC.
- Some payers require separate charge capture for discarded amounts.
Stress Agents Billing (J-Codes)
Common pharmacologic stress agents used with PET:
- J2785 – Regadenoson
- J0153 – Adenosine
- J1245 – Dipyridamole
- J1250 – Dobutamine
Documentation must include:
- Agent name
- Dose (mg or mcg/kg/min)
- Duration
- Adverse reactions, if any
- Indication for pharmacologic stress
Documentation Requirements for PET Perfusion Billing
Strong documentation is essential because PET is a high-cost service.
Required Elements
Clinical Indication
Examples:
- Intermediate-to-high probability of CAD
- Prior equivocal SPECT/Stress Echo
- Multivessel CAD evaluation
- Microvascular dysfunction suspected
- Pre-operative evaluation when SPECT is inadequate
- Obesity or large body habitus limiting SPECT accuracy
Stress Protocol
Include:
- Pharmacologic agent used
- Dose and administration method
- Hemodynamic response
- ECG changes
- Symptoms and timing
- Reason for early termination (if any)
Radiopharmaceutical Details
Must include:
- Type of PET tracer (Rb-82, N-13)
- Dose measurements (mCi)
- Time of injection
- Rest and stress administration timestamps
Image Acquisition Details
- Gated vs non-gated
- PET scanner type (if required by payer)
- Reconstruction details
- Attenuation correction information
Interpretation Requirements
A valid PET perfusion interpretation must include:
- Rest perfusion analysis
- Stress perfusion analysis
- Defect characterization: fixed, reversible, size, severity
- Wall motion and thickening
- LV ejection fraction
- Stress response summary
- Interpretation of global vs regional ischemia
- For 0482T: MBF values + MFR ratios
When PET Myocardial Perfusion Requires Prior Authorization
Most major commercial payers require prior authorization for PET MPI because of high cost and availability concerns.
Common reasons authorization is required:
- The patient previously had an SPECT, but the results were inconclusive
- Patient cannot undergo SPECT (obesity, attenuation, breast tissue artifacts)
- Evaluation of suspected multivessel disease
- Evaluation for microvascular dysfunction
- Post-CABG evaluation
- Alternative to coronary CT angiography in certain cases
Medicare rarely requires prior authorization, but MACs may restrict Category III add-on codes.
Bundling & NCCI Edits Specific to PET Myocardial Perfusion
1. Stress ECG (93015–93018)
Often NOT separately payable, depending on the payer:
- Many treat ECG monitoring as part of the PET stress procedure.
- Some permit 93018 (interpretation only).
2. CT Attenuation Correction
Most PET scanners use low-dose CT for attenuation correction.
Billing note:
- Many payers deny separate CT codes, classifying attenuation CT as bundled.
3. Radiopharmaceutical Supply & Waste
Strict documentation is required for appropriate billing of dose and waste.
4. E/M on the Same Day
E/M must be significantly separate with modifier 25 if billed.
5. Blood Flow Quantification (0482T)
Not bundled but requires:
- Separate documentation
- Medical necessity
- Clear quantitative values
Frequent Denials & How to Avoid Them
Denial 1: “Non-covered radiopharmaceutical.”
Solution:
Confirm payer coverage for Rb-82 versus N-13 ammonia.
Denial 2: “Unclear medical necessity for PET over SPECT.”
Solution:
Documentation must explicitly state why PET is preferred, e.g.,
“Prior SPECT was non-diagnostic due to breast attenuation artifact.”
Denial 3: “Stress testing components included.”
Solution:
If billing 93018, show a separate ECG interpretation.
Denial 4: “Missing rest or stress documentation.”
Solution:
State clearly:
- Images acquired
- Interpretation performed
- Reasons for single-phase
Denial 5: Invalid or missing radiopharmaceutical units
Solution:
Use correct HCPCS units and show wastage.
Denial 6: “0482T experimental”
Solution:
Check payer policy; appeal with literature when appropriate.
Practical Workflow Recommendations for Clinics & Imaging Centers
Build a PET MPI Checklist
Include fields for:
- Indication
- Patient prep
- Stress agent
- Tracer dose
- Imaging timestamps
- Rest/stress complete
- Blood flow quantification
- Interpretation elements
Standardize Reporting Templates
Ensure all required diagnostic elements appear in every PET MPI report.
Confirm Payer Policy Before Scanning
Particularly for:
- Commercial payers
- Category III code coverage
- Radiopharmaceutical authorizations
Train Staff on HCPCS Units
Dose-related denials are common and avoidable.
Conclusion
Myocardial perfusion PET is one of the most precise tools for evaluating coronary perfusion, microvascular disease, and myocardial viability, but it also carries some of the most technical documentation and coding requirements in cardiovascular imaging. Accurate reporting of tracer doses, acquisition phases, interpretation elements, and the correct CPT assignment (78429–78431) is essential for compliance and clean reimbursement. Payers closely review medical necessity, prior authorization, and whether PET was appropriately selected over SPECT based on clinical complexity. Well-structured documentation and clear imaging reports significantly reduce denials, audits, and billing delays. For practices that want to ensure consistent accuracy across nuclear cardiology workflows, internal QA processes, and experienced billing partners—such as Global Tech Billing LLC—can support proper coding alignment and payer compliance.
FAQs
1. What CPT codes are used for myocardial perfusion PET?
CPT 78429–78431 cover rest-only, stress-only, and rest–stress PET myocardial perfusion studies.
2. What does CPT 78429 represent?
78429 is used for rest-only PET myocardial perfusion imaging.
3. When is CPT 78430 billed?
78430 is billed for stress-only myocardial perfusion PET.
4. What is CPT 78431 used for?
78431 is used when both rest and stress PET perfusion imaging are performed on the same date.
5. Are radiopharmaceuticals separately billable with myocardial perfusion PET?
Yes. Rubidium-82 (A9555) or N-13 ammonia (A9558) may be billed separately based on payer rules.
6. Is prior authorization required for PET myocardial perfusion imaging?
Most commercial plans require it; Medicare coverage depends on regional MAC policies and clinical indications.
7. Are interpretation and technical components split for PET?
Yes. Use modifiers 26 (professional) and TC (technical) when components are billed by different entities.
8. What documentation is required for PET perfusion billing?
Clinical indication, stress protocol, tracer type/dose, image interpretation, functional findings, and physician signature.
