CPT code 78582 represents a combined pulmonary ventilation and perfusion (V/Q) nuclear medicine scan that images both air flow and blood flow in the lungs. Nationally, this diagnostic study is a key tool for evaluating suspected pulmonary embolism and other causes of ventilation–perfusion mismatch, with implications for emergency, inpatient, and outpatient care pathways. The procedure’s dual assessment capability makes it clinically valuable when computed tomography pulmonary angiography is contraindicated or when radiation exposure or contrast use must be minimized.

Key payers examined include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Coverage and coding practices for 78582 influence utilization patterns, site-of-service choices, and reimbursement across hospital outpatient departments and freestanding imaging centers.

Readers will find a concise national overview of the code’s clinical role, typical sites of service, common modifiers and billing considerations (where available), and the types of policy items that affect coverage and payment. The publication summarizes benchmarking context, highlights areas where policy updates commonly arise (medical necessity criteria, prior authorization, and comparative imaging algorithms), and provides clinical context to help billing and compliance teams align documentation with payer expectations. Data not available in the input is noted where applicable.