Summary & Overview
CPT 78609: PET Brain Imaging to Assess Function and Blood Flow
CPT code 78609 represents a PET (positron emission tomography) scan of the brain, a diagnostic nuclear imaging test that assesses brain function and cerebral blood flow. As an advanced functional imaging modality, PET brain scans are important for evaluation of neurodegenerative disorders, seizure focus localization, and certain cerebrovascular and oncologic indications. Nationally, PET brain imaging influences diagnostic pathways, care planning, and utilization of specialty imaging resources.
Key payers covered in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise briefing on the clinical context of PET brain imaging, the typical service and site of care, and how this service is addressed across major payers. The publication also summarizes available benchmarks and payer policy themes, where present, and highlights areas where policy updates or utilization considerations may affect access and billing practices.
This summary is intended for clinical managers, coding and billing staff, and policy analysts seeking a national perspective on CPT code 78609, including clinical relevance, payer coverage context, and topics to consider when managing PET brain imaging services.
Billing Code Overview
CPT code 78609 describes a positron emission tomography (PET) scan of the brain used to evaluate brain function and cerebral blood flow. This is a diagnostic nuclear imaging procedure that captures metabolic and perfusion information to support evaluation of neurologic conditions.
Service type: Diagnostic nuclear medicine — PET brain imaging
Typical site of service: Hospital outpatient imaging center or freestanding imaging facility
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult referred by a neurologist or primary care physician for evaluation of cognitive decline, suspected neurodegenerative disease (for example, Alzheimer disease), or to assess regional cerebral blood flow after cerebrovascular events. The patient arrives at an outpatient radiology or nuclear medicine department or an inpatient hospital imaging center. After verifying indication and obtaining informed consent, the nuclear medicine team administers a radiotracer (commonly FDG or perfusion tracers) and performs a PET brain acquisition. Vital signs are monitored, and contraindications (recent contrast, pregnancy, or inability to cooperate) are reviewed. Images are reconstructed and interpreted by a board-certified nuclear medicine physician or neuroradiologist; a report documents tracer uptake patterns, compares with prior studies when available, and provides an impression that guides clinical management such as dementia workup, seizure focus localization, or assessment of cerebral perfusion post-stroke. Typical sites of service include outpatient imaging centers, hospital outpatient departments, and inpatient radiology suites.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the physician interpretation of the PET study separate from technical services. |