CPT 78431 describes positron emission tomography (PET) myocardial perfusion imaging performed as multiple studies at rest and/or stress, with concurrently acquired computed tomography for attenuation correction and anatomical review. It is one of the cardiac PET codes the AMA introduced effective January 1, 2020 (78429–78433), which replaced the older combined-reporting approach with single codes that bundle the CT attenuation acquisition into the PET study itself. When performed, quantification of absolute myocardial blood flow is included in 78431 — it is not reported separately when it is part of this study.
Report 78431 when the cardiologist or nuclear medicine physician performs a rest and stress (or multiple-study) PET myocardial perfusion examination and a CT is acquired in the same session specifically for attenuation correction and anatomical review. Typical clinical contexts include evaluation of known or suspected coronary artery disease in patients where SPECT is likely to be non-diagnostic — larger body habitus, prior equivocal SPECT, or when absolute myocardial blood flow quantification will change management. The radiopharmaceutical (for example rubidium-82 or N-13 ammonia) is not included in the CPT code and is reported separately with the appropriate HCPCS supply code per payer policy.
Do not report 78431 for a single-study (rest only or stress only) perfusion PET — that is 78430 territory. Do not report it when no concurrent CT is acquired for attenuation correction; the non-CT multiple-study perfusion code applies instead (78492 family was deleted in 2020 — use the current 78429–78433 code that matches the acquisition). Do not separately report a diagnostic CT of the chest, a calcium scoring study (75571), or myocardial blood flow quantification on top of 78431 for the same session — the attenuation CT and flow quantification are components of the code, and a same-session diagnostic CT requires its own distinct medical necessity and documentation. Do not report SPECT myocardial perfusion (78451–78452) for the same session.
The report must identify the radiopharmaceutical and dose, the stress method (pharmacologic agent or exercise), rest and stress image findings by vascular territory, the CT attenuation correction acquisition, and — when performed — the quantified myocardial blood flow and flow reserve values with interpretation. The ordering indication needs to support medical necessity under the Medicare contractor’s LCD or the commercial payer’s cardiac imaging policy, and most commercial payers require prior authorization for cardiac PET, so the authorization number should be on file before the date of service.
No. When absolute myocardial blood flow quantification is performed as part of the study, it is included in 78431 by the code descriptor ("when performed"). Reporting it separately for the same session is unbundling and a common audit finding.
Not when it was acquired for attenuation correction and anatomical review — that acquisition is part of the code. A separately billable diagnostic chest CT would need its own order, its own medical-necessity indication, and a complete separate interpretation.
The tracer is not part of the CPT code. In the office or IDTF setting it is reported with the matching HCPCS supply code — for example A9555 for rubidium-82 — with units per the payer’s policy. Hospital outpatient billing follows the facility’s OPPS packaging rules instead.
Cardiac PET perfusion imaging is covered by Medicare for appropriate indications, but coverage details, frequency expectations, and documentation requirements come from the local Medicare Administrative Contractor’s policies, so verify the applicable LCD/LCA before scheduling.
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