Cardiac PET/CT hybrid imaging has become a core diagnostic modality for evaluating myocardial perfusion, coronary flow reserve (CFR), viability, inflammation, and infiltrative diseases. Compared to SPECT, PET offers higher spatial resolution, absolute flow measurement, and superior attenuation correction. When fused with CT, PET/CT provides additional anatomic localization and coronary calcification data.
Because PET/CT uses both nuclear medicine (PET) and computed tomography (CT) components, the billing rules, CPT codes, radiopharmaceutical reporting, and supervision requirements are more complex than single-modality imaging. This guide provides a complete educational reference for documentation, coding, payer rules, bundling, and appropriate use criteria—strictly factual and designed to help practices avoid denials and audits.
Understanding Cardiac PET/CT Hybrid Imaging
Hybrid PET/CT imaging merges:
1. PET Perfusion or Metabolic Imaging
- Measures blood flow (rest/stress)
- Detects ischemia
- Evaluates myocardial viability
- Provides quantification (e.g., CFR, MBF)
2. CT Component
- Used for attenuation correction (AC)
- May include diagnostic CT if medically necessary
- May include non-contrast CT calcium scoring, depending on payer and indication
Billing requirements depend on:
- Whether CT is non-diagnostic (AC only)
- Whether CT is diagnostic
- Whether PET is perfusion, metabolic, or combined
CPT Codes for Cardiac PET & PET/CT Hybrid Imaging
PET Myocardial Perfusion
- CPT 78430 – Myocardial perfusion PET, single study
- (includes rest OR stress; not both)
- CPT 78431 – Myocardial perfusion PET, multiple studies
- (rest + stress, with/without quantification)
PET/CT Hybrid Codes (Non-cardiac PET, but used when the CT component is diagnostic)
- 78814 – PET/CT, limited area, attenuation correction + anatomical localization
- 78815 – PET/CT, limited area, diagnostic CT
- 78816 – PET/CT, whole-body, diagnostic CT
Important:
Cardiac PET perfusion is billed with 78430–78431.
78814–78816 are used only when a diagnostic CT is performed as part of the hybrid study.
Attenuation correction CT alone is not billed separately.
Clinical Scenarios When Cardiac PET/CT Is Used
1. Myocardial Perfusion (Rest and/or Stress)
Indications include:
- Suspected or known CAD
- Evaluation after inconclusive SPECT
- Intermediate-to-high-risk patients
- Microvascular dysfunction
- Balanced ischemia assessment
- Pre-operative cardiac risk evaluation
2. Myocardial Viability
PET metabolic imaging (FDG) detects:
- Hibernating myocardium
- Mismatch between perfusion and metabolism
- Areas of predicted recovery post-revascularization
3. Sarcoidosis Evaluation
FDG PET detects active myocardial inflammation.
4. Cardiac Amyloidosis
Although less common than nuclear PYP imaging, PET/CT may be used in certain settings.
5. Coronary Flow Reserve Quantification
A unique advantage of PET perfusion imaging.
Diagnostic CT Component in Hybrid PET/CT
PET/CT studies may include a CT scan for:
- Attenuation correction only
- Coronary artery calcium scoring
- Coronary CT angiography (rare in PET labs)
- Non-contrast anatomic localization
- Diagnostic evaluation of thoracic structures
Billing depends on the type of CT performed.
1. Attenuation Correction CT (AC-CT)
- Bundled
- NOT separately billable
2. Non-Contrast Localization CT
If performed solely for anatomical localization:
- Use PET/CT codes 78814–78816 based on the coverage area.
3. Diagnostic CT
If medically necessary and ordered:
- Bill with 78815 or 78816
- Requires:
- Full diagnostic CT protocol
- CT-specific documentation
- CT interpretation
Without documentation of diagnostic intent, → payer will deny the CT portion.
Radiopharmaceutical Billing
Cardiac PET commonly uses the following radiopharmaceuticals:
Perfusion Agents
- Rubidium-82 (Rb-82) – HCPCS A9555
- Ammonia N-13 – HCPCS A9552
Metabolic Agents (Viability/Sarcoidosis)
- FDG (Fluorodeoxyglucose) – HCPCS A9552
Billing requirements include:
- Dose in mCi
- Time of administration
- Lot number
- NDC (payer dependent)
- Wastage documentation if billed (JW modifier)
Supervision & Staff Requirements
Direct physician supervision is required for:
- Pharmacologic stress
- Administration of Rb-82
- Most PET perfusion studies
General supervision may apply to:
- FDG PET metabolic studies
Requirements vary by payer and accreditation body (e.g., CMS, ACR, IAC Nuclear/PET).
Documentation Requirements for Cardiac PET/CT
1. Clinical Indication/Medical Necessity
Must specify:
- Symptoms (e.g., exertional pain, dyspnea)
- Risk factors
- Prior imaging (e.g., equivocal SPECT or ECG stress)
- Pre-procedure intent
- Suspected CAD, viability, sarcoidosis, etc.
2. Radiopharmaceutical Details
- Name of tracer
- Dose (mCi)
- Injection time
- Imaging start time
- Any reinjections
3. Stress Details (if applicable)
- Pharmacologic agent (regadenoson, adenosine, dobutamine)
- Dose
- Duration
- Symptoms during the test
- Peak hemodynamics
4. CT Component Documentation
- Whether an AC-only CT was used
- Whether CT was diagnostic (requires separate interpretation)
- Radiation parameters (kVp, mAs, dose index)
5. Perfusion Findings
- Perfusion defects
- Reversible vs fixed
- Ischemic territory
- Scar patterns
6. Quantitative PET Data
If measured, include:
- MBF (rest/stress)
- CFR values
- Regional and global flow reserve
7. Report Requirements
A complete PET/CT report should include:
- Technique
- Radiopharmaceutical
- Stress or rest protocol
- CT findings (if diagnostic)
- Perfusion defects
- LV function and wall motion
- Quantitative data
- Impression and recommendation
Reports must be signed by the interpreting cardiologist or nuclear medicine physician.
Bundling & Coding Considerations
1. Attenuation CT is always bundled
Do not bill diagnostic CT unless:
- There is a separate clinical reason
- The CT protocol is diagnostic
- Full CT interpretation exists
2. PET perfusion cannot be billed with PET metabolic (FDG) on the same day
Unless ordered for:
- Sarcoidosis AND viability
- Most payers consider it medically unlikely.
3. Stress Test Codes
Do not bill 93015–93018 with PET pharmacologic stress unless:
- Stress is separately performed for non-PET reasons
- Most payers bundle stress supervision into PET.
4. PET + SPECT
Rarely billable together except for specific complex scenarios, such as:
- PET viability + SPECT perfusion if ordered independently
- Documentation must prove separation of purpose.
5. Contrast Media for CT
If diagnostic CT is used:
- Report contrast HCPCS separately (if applicable)
Requirements for Prior Authorization
Most commercial insurers require prior authorization for:
- PET perfusion
- FDG metabolic PET
- PET/CT diagnostic CT
- PET with quantitative blood flow analysis
Medicare may require:
- Documentation of medical necessity
- Adherence to appropriate use criteria (AUC) via qualified CDS tools
Failure to obtain authorization is one of the highest denial categories in cardiac PET.
Common Denial Reasons & How to Avoid Them
1. Missing clinical indication
Include clear symptoms and rationale.
2. Billing CT without diagnostic documentation
AC-only CT cannot be billed.
3. Incorrect PET code selection
Use:
- 78430: single study
- 78431: multiple studies
4. Missing tracer dosing documentation
Include dose, time, and lot/NDC.
5. Overlapping services
Avoid billing PET perfusion + PET viability without a clear justification.
6. Incomplete stress documentation
Include agent, dose, and hemodynamics.
7. Lack of PET quantification detail
If billing for quantitative flow, include measured values.
8. Attempting to bill stress ECG codes
Most stress supervision is bundled.
Compliance & Audit Considerations
PET/CT services are high-cost and subject to strict audit scrutiny. Audit focus areas include:
- Duplicate studies
- Missing medical necessity
- PET vs CT mismatches
- Incorrect PET code (single vs multiple study)
- Billing diagnostic CT during PET without separate indications
- Missing quantitative PET documentation
Internal audits should review:
- Tracer usage logs
- Stress supervision records
- PET/CT image storage requirements
- Supervision qualifications
Practices often maintain templates to standardize documentation for perfusion, viability, and CT findings. Many cardiology groups collaborate with RCM experts such as Global Tech Billing LLC to maintain compliant PET/CT workflows.
FAQs
1. What CPT codes are used for cardiac PET/CT hybrid imaging?
Cardiac PET perfusion uses 78430–78431, while PET/CT hybrid imaging uses 78814–78816 when diagnostic CT is performed.
2. Is CT attenuation correction separately billable?
No. Attenuation correction CT is bundled and should not be billed separately.
3. When can a diagnostic CT be billed with cardiac PET?
Only when medically necessary, ordered separately, and accompanied by a full diagnostic interpretation.
4. What radiotracers are used for cardiac PET?
Common tracers include rubidium-82 (A9555), N-13 ammonia (A9552), and FDG (A9552).
5. Is stress supervision billed separately for PET?
No. Stress testing for PET (regadenoson, adenosine, etc.) is bundled unless performed for reasons unrelated to the PET study.
6. Do PET perfusion and PET viability use separate codes?
Yes. Perfusion uses 78430–78431; viability uses FDG PET codes under metabolic imaging rules.
7. What documentation is required for PET/CT billing?
Document clinical indication, radiotracer dosing, stress parameters, CT type (AC or diagnostic), perfusion results, and quantification values.
8. Do payers require prior authorization for cardiac PET?
Most commercial plans require prior authorization for PET perfusion, PET viability, and PET/CT diagnostic components.
