CPT code 78597 identifies a pulmonary perfusion nuclear medicine procedure that performs quantitative analysis of differential pulmonary artery blood flow. This diagnostic test evaluates regional lung perfusion and can be used in clinical pathways for pulmonary embolism assessment, preoperative evaluation, and other causes of asymmetric pulmonary blood flow. The code is nationally relevant because it supports decisions about imaging strategies, anticoagulation, and surgical planning in cardiopulmonary care.

Key payers covered in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical purpose and service setting for the code, guidance on typical sites of service, and notes about common billing considerations. Where available, the publication presents benchmarks and coverage patterns, as well as references to policy language and coding guidance that affect claim adjudication.

This summary helps clinicians, coding professionals, and billing managers understand what CPT code 78597 represents, why it matters in patient care workflows, and the practical contexts in which the service is delivered. Data not available in the input is identified where applicable.