The Current Procedural Terminology (CPT) system provides a uniform language for documenting medical services and procedures. These numerical identifiers allow healthcare providers and insurance companies to communicate accurately about services rendered. Understanding these codes is necessary for proper medical billing, tracking of services, and ensuring appropriate reimbursement.
Defining CPT Code 71275
CPT code 71275 specifically identifies a Computed Tomographic Angiography (CTA) of the chest. This diagnostic procedure provides detailed images of the blood vessels within the chest cavity, excluding the coronary arteries. The focus is on visualizing the structure and blood flow of major vessels, such as the aorta and pulmonary arteries.
A defining characteristic of this code is the mandatory inclusion of contrast material, typically an iodine-based agent, which is injected intravenously. This material enhances the clarity of the blood vessels, making blockages, tears, or aneurysms visible against the surrounding soft tissues. The CPT code also encompasses any non-contrast images acquired during the study, along with the necessary advanced image post-processing to create detailed views.
Clinical Applications of the Procedure
The CTA chest is utilized to assess the great vessels of the chest for a variety of serious conditions. One of the most common applications is the urgent diagnosis of a Pulmonary Embolism (PE), which involves a blockage in one of the pulmonary arteries, often caused by a blood clot.
Another frequent indication is the evaluation of acute aortic syndrome, which includes conditions such as Aortic Dissection. This is a medical emergency where the layers of the aorta’s wall separate, and the CTA provides precise visualization of the tear and the extent of the dissection. Clinicians also use this procedure to assess for thoracic aortic aneurysms, which are abnormal bulges in the aorta that can rupture. Furthermore, the detailed vascular mapping is valuable for pre-surgical planning or for evaluating congenital abnormalities of the heart and great vessels.
Understanding the Imaging Process
The CTA chest procedure begins with the patient lying on the computed tomography (CT) scanner table, where an intravenous line is inserted, typically into a vein in the arm, to administer the contrast agent. The iodinated contrast material is injected at a high flow rate, and the process is precisely timed to ensure the scan captures the contrast when it is concentrated within the targeted arteries. This synchronization is achieved through a technique called “bolus tracking.”
Bolus tracking involves repeatedly scanning a small area of a target vessel, such as the pulmonary artery or aorta, with low-dose radiation to monitor the density of the contrast material in real-time. Once the density, measured in Hounsfield units, reaches a pre-set threshold, the full diagnostic scan is automatically triggered. The patient is also given breath-holding instructions during the scan acquisition to minimize motion artifacts, which can blur the images and compromise the diagnostic quality. The resulting raw data is then processed by a computer to create high-resolution, three-dimensional images of the vascular anatomy.
Billing and Reimbursement Context
Because CPT code 71275 is defined as including contrast material, the cost of the contrast agent itself is integrated into the overall charge and is not billed separately. When the service is billed, specific modifiers are used to clarify who performed which part of the service.
Modifier -26 is appended when the bill is only for the professional component, meaning the radiologist’s interpretation and report. Conversely, modifier -TC is used when the bill is for the technical component, covering the use of the equipment, supplies, and the work of the technologists. Due to the high cost of advanced imaging, most payers require prior authorization before the procedure is performed. The medical necessity of the CTA must be supported by the appropriate diagnosis codes, known as ICD-10 codes, which link the patient’s condition to the need for this specific diagnostic test.