Summary & Overview
CPT 78598: Pulmonary Ventilation and Perfusion Quantitative Scan
CPT code 78598 represents a combined pulmonary ventilation and perfusion nuclear medicine scan that provides quantitative analysis of differential ventilation and perfusion across the lungs. This diagnostic imaging procedure is nationally important because it informs the detection and management of conditions that impair regional lung function, including pulmonary embolism and chronic perfusion abnormalities. Its quantitative nature supports clinical decision-making for diagnosis, treatment planning, and monitoring disease progression.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of typical clinical indications, service and site-of-service context, and the role of quantitative V/Q (ventilation-perfusion) imaging in the diagnostic pathway. The publication also outlines benchmarks and coverage patterns where available, notes coding considerations, and summarizes how this service fits into broader imaging and pulmonary care workflows. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 78598 describes a combined pulmonary ventilation and perfusion nuclear medicine scan that quantitatively evaluates the distribution of air (ventilation) and blood flow (perfusion) within the lungs. The procedure is used to assess differential pulmonary ventilation and perfusion, commonly performed to evaluate suspected pulmonary embolism, chronic thromboembolic disease, or other conditions that alter regional lung ventilation or perfusion.
Service Type: Nuclear medicine diagnostic imaging with quantitative ventilation and perfusion analysis
Typical Site of Service: Hospital outpatient imaging center, hospital radiology/nuclear medicine department, or freestanding imaging center.
Clinical & Coding Specifications
Clinical Context
A 67-year-old patient with a history of chronic obstructive pulmonary disease and new-onset unilateral pleuritic chest pain presents with unexplained dyspnea and an elevated clinical suspicion for pulmonary embolism. The referring pulmonologist or emergency physician orders a quantitative ventilation–perfusion nuclear medicine study to evaluate regional ventilation and perfusion and to identify or exclude perfusion defects consistent with pulmonary embolism. The patient arrives at an outpatient nuclear medicine or hospital radiology department. The nuclear medicine technologist obtains informed consent, reviews allergies and pregnancy status, and performs a ventilation scan (commonly using inhaled radiotracer such as Technegas or aerosolized radioaerosol) followed by a perfusion scan (intravenous injection of macroaggregated albumin labeled with technetium-99m). Images are acquired in multiple projections and processed for quantitative analysis of differential pulmonary ventilation and perfusion. A radiologist or nuclear medicine physician interprets the combined study, documents quantitative findings (including percentage perfusion by lung or lobe), and issues a report that guides clinical management such as anticoagulation decisions or further imaging like CT pulmonary angiography. Typical sites of service include hospital outpatient departments, hospital inpatient wards, and freestanding or hospital-based nuclear medicine suites. Service type: diagnostic nuclear medicine ventilation–perfusion (V/Q) study involving both ventilation and perfusion components.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 |