CPT® Code 0331T

Myocardial sympathetic innervation imaging is a specialized diagnostic procedure that focuses on the sympathetic nervous system (SNS) innervation of the heart. The heart contains a significant number of nerves that are part of the SNS, which plays a crucial role in regulating cardiac function. This imaging technique utilizes a radiolabeled compound known as metaiodobenzylguanidine (I-mIBG) to visualize and assess the distribution of these cardiac nerves. By measuring the heart to mediastinum (H/M) ratio of norepinephrine (NE) reuptake, healthcare professionals can gain insights into the sympathetic nerve activity within the heart. This information is vital as it can help identify various disease processes and assess mortality risks associated with cardiac conditions. During the procedure, I-mIBG is administered intravenously while the patient is at rest, allowing for a clear assessment of the heart's sympathetic innervation. The imaging process involves obtaining radiologic planar views of the chest shortly after the administration of I-mIBG, followed by additional imaging at a later time to evaluate changes in nerve activity and uptake. The qualitative assessment involves a visual evaluation of the images, while a quantitative analysis is performed to calculate the H/M ratio, providing a comprehensive understanding of norepinephrine retention by sympathetic neurons in the heart.