The following article is published by the American Hospital Association’s Central Office on HCPCS in collaboration with the American College of Radiology.
Computed tomographic angiography (CTA), a less-invasive technique for imaging vessels (both arteries and veins), has gained widespread usage in clinical practice. Prior to the introduction of this new technique, vascular evaluation was performed primarily by invasive catheter angiography. CTA offers important advantages over conventional angiography, which only depicts the vascular lumen. With CTA, additional information is provided, including vessel wall thickness, relationship to adjacent structures, enhanced depiction of the venous anatomy, and parenchymal information about the target organ and other structures within the scan range and field of view.
Description of procedure
The acquisition of CTA image data includes skeletal anatomy, soft tissues and vessels. In CTA, a few unenhanced (without contrast) images as well as enhanced CT data is obtained. Following imaging, 2D or 3D reformatted (reconstruction) images are typically performed.
Imaging of the vessels is not necessarily CTA. The key distinction between CTA and CT is that CTA includes reconstruction post-processing of angiographic images of the vessels and interpretation. If reconstruction post-processing is not done, it is not a CTA study.
The following eight codes were developed in 2001 to describe CTA:
70496 CTA, Head
70498 CTA, Neck
71275 CTA, Chest
72191 CTA, Pelvis
73206 CTA, Upper extremity
73706 CTA, Lower extremity
74175 CTA, Abdomen
75635 CTA, Abdominal aorta and bilateral iliofemoral lower extremity runoff
The descriptors for the above codes all specify, “without contrast material(s), followed by contrast material(s) and further sections, including image post-processing.” The portion of the CTA exam referred to as “without contrast material(s)” represents the images taken to calibrate the scanner and to identify the anatomic region to be evaluated during the “with contrast” portion of the study. The phrase “imaging post-processing” in the descriptor refers to the 2-D and 3-D reconstructions performed. Therefore, CPT® code 76375 (coronal, sagittal, multiplanar, oblique, three-dimensional and/or holographic reconstruction of computerized tomography, magnetic resonance imaging or other tomographic modality) should not be coded separately for CTA studies, since imaging post-processing is included in the descriptor.
Injection of contrast material is part of the “with contrast” CTA procedure; therefore, it is not appropriate to separately report the code for the administration of contrast. The supply of low osmolar contrast, however, may be reported separately with the appropriate HCPCS Level II code for the contrast material used. Low osmolar contrast is always used for CTA, because CTA is always performed with a power injector.
Code 75635 was developed to appropriately identify an abdominal aorta with bilateral iliofemoral runoff CTA. Therefore, although the distal abdominal aorta and iliofemoral vessels are in the pelvis, it would not be appropriate to code a CTA of the pelvis when the procedure is performed as a runoff study. The cross-references under CTA CPT® codes 72191 (pelvis), 73706 (lower extremity), and 74175 (abdomen) specify that 75635 should be used for CTA aorto-iliofemoral runoff. If a complete CTA study of the abdomen and a complete CTA study of the pelvis from the diaphragm to the symphysis pubis were performed, without a runoff examination, it would be appropriate to code for both a CTA abdomen and CTA pelvis.
If computed tomography (CT) venography is performed, the CTA procedure code would be the appropriate code to assign. Angiography refers to coding of the vasculature, which includes both arteries and veins.
Computed tomography (CT) in conjunction with CTA
Relative to the total number of procedures performed, the performance of separate CT and CTA examinations of the same anatomy-specific region on the same day would be infrequent. There may be instances, however, when findings on an anatomic CT will raise clinical questions that require performance of a CTA on the same day in order to answer. For example, a patient who is experiencing continuous or severe abdominal pain is referred to radiology for an abdominal CT scan. The CT study demonstrates a tumor in the head of the pancreas. Based on this finding, it is determined that a CTA should be performed as soon as possible to evaluate the vascular invasion by the tumor. A subsequent CTA, involving a new data acquisition, is performed and demonstrates the tumor encasing the pancreaticoduodenal artery and invading the portal vein, rendering the tumor inoperable. In this scenario, although both procedures are performed during the same session or on the same day, the CT and CTA are separate and distinct procedures that use separate data sets and, therefore, are coded separately.
Distinctions between computed tomographic angiography (CTA) and magnetic resonance angiography (MRA)
With the development of the magnetic resonance angiography codes, and more recently, the computed tomographic angiography codes, there has been much confusion about which services were included in the development of these codes and which services should be coded separately.
Computed tomographic angiography—A major distinction between CTA and MRA is that the acquisition of CTA image data includes skeletal anatomy, soft tissues and vessels. In CTA, typically, a few unenhanced images are taken to calibrate the scanner and localize the anatomic region to be evaluated during the contrast-enhanced scan. The patient is then given a rapid injection of intravenous contrast to enhance the blood vessels. A full set of enhanced CT data is then obtained, which includes all of the anatomy in the area to be examined; an enhanced CT of that region and field-of-view is included in the CTA. Following the imaging, 2D or 3D reformatted images are typically performed. The 2D reformatted images can be created in multiple planes, then interpreted, annotated and archived as hard copy, electronic files or both. The 3D or volume-rendered reconstructions are typically evaluated in multiple projections.
The work of 3D reformatting is quite extensive, usually performed on a separate workstation. Vessels are highlighted and featured for viewing and noncritical areas, such as bony structure and surrounding soft tissues, are eliminated in order to provide a focused evaluation of the vasculature. The entire process, including the acquisition of localizing images and contrast-enhanced data, the reformatting of those images and the interpretation of both the source images and the reconstructions that define the work of a CTA study and is included in the respective CPT® codes.
Magnetic resonance angiography—Unlike CTA, MRA is an imaging study of the vessels only. Images of the vessels are acquired, with the other tissues nulled by the radiofrequency (RF) pulse sequence, and then reformatted to optimize evaluation of an abnormality of a vessel. Note that MRA can be performed without contrast, with contrast or possibly without contrast followed by contrast if the noncontrast study is nondiagnostic.
An MRA demonstrates vascular morphology and function noninvasively. Blood flowing through vessels emits a unique signal during the MRI process. Through selection of appropriate pulse sequences, the blood flow itself can be used to generate a bright or dark signal from which detailed anatomic views of the vessels, similar to angiograms, can be constructed. These signals are capable of providing flow information. The detailed views of the arteries and veins generated by an MRA make it particularly useful as a means of identifying the existence of vascular abnormalities or assessing the need for further diagnostic or therapeutic procedures.
As with CT and CTA it may be necessary to perform both an MRI and MRA to answer the clinical question. If two separate and distinct studies are done, both should have separate reports, and both should be coded.
For example, a patient with clinical symptoms suggestive of stroke may undergo an MRI of the brain to determine if there has been brain infarction, and an MRA of the neck to determine if there is carotid stenosis. In this example, both procedures represent separate procedures and result in separate reports of diagnostic findings.
Code 76375 (2D/3D reconstruction) should not be coded with either CTA or MRA examinations, as the postprocessing of the vascular images is included in the CTA and MRA codes.
Distinction between CT and CTA costs, charges and reimbursements
Is your hospital adequately computing CTA costs and charges? If CTA is to be reimbursed adequately, hospital and radiology administrators urgently need to check their chargemasters for CTA relative to “CT without contrast followed by with contrast” studies. Since CTA involves all the costs of CT studies plus the added costs of expensive image-processing workstations, added technologist time, and additional images from post-processing, etc., CTA costs and charges should always be higher than those for the analogous CT exams. Yet, analyses of the 2001 CMS claims data demonstrate that less than 50 percent of all hospitals actually charged more for CTA than for CT.
Background—Prior to 2001, CTA was billed as two distinct and separate procedures identified by two codes: a CT anatomy-specific scan code, plus a separate 3-D reconstruction code. In 2001 eight new CPT codes-based on body region scanned-were created for CT angiography (CTA). These new CTA codes were created so that all the work of CTA, including the CT images acquired and the additional cost of 3-D image post-processing of the vessels, would be appropriately reflected. The additional CTA costs related to the image post-processing are substantial and include technologist processing time for creating 3-D CTA images (average 53 minutes according to cost survey data); cost of 3-D imaging workstation; additional films and supplies for the 3-D images (30-40 additional 3-D images per study); and hospital overhead costs.
Unfortunately for hospitals, the new CTA codes were grouped into the same ambulatory payment category (APC) as CT without contrast followed by with contrast studies; there was no incremental reimbursement for the additional image post-processing that had previously been billed separately. Ideally CTA should have been recognized as a new technology until cost data could be collected to determine its APC relative weight. The Centers for Medicare and Medicaid Services (CMS) chose not to recognize it as a new technology.
In 2002, the ACR requested that CMS move CTA to a separate reimbursement category and reimburse it at a rate comparable to CT plus the 3-D code (76375). CMS agreed for 2003 to move CTA to a new APC category (CTA is now in APC 662, while CT without/with contrast remains in APC 333). Unfortunately, CMS also applied faulty 2001 claims data to set the reimbursement, and CTA (APC 662) is only paid $5 more than CT (APC 333) for 2003.
This faulty data resulted from confusing information and widespread misunderstanding among hospitals and radiology administrators about how to report costs and set charges for the new CTA codes. As stated above, if CTA is to be reimbursed adequately, hospital and radiology administrators must report their costs and charges for CTA relative to “CT without followed by with contrast” studies appropriately. CTA costs and charges should always be higher than those for the analogous CT exams.
Ultimately, patients benefit when hospitals report their costs and charges appropriately and are adequately reimbursed for CTA as a cost-effective and safer alternative to catheter angiography for many vascular imaging clinical applications. Even so, less than half of all hospitals that submitted claims for both CT and CTA in 2001 actually charged more for CTA. This proves that the majority of hospitals charged incorrectly in 2001 for CTA, which resulted in diminished CTA reimbursement rates in 2003. Hospitals that are charging less for CTA relative to CT are urged to submit their CTA claims so that CTA charges appropriately reflect additional costs involved in CTA post-processing relative to CT. If all hospitals correctly submit their CTA claims to appropriately reflect the higher costs and charges for CTA relative to CT, CTA reimbursements in the hospital outpatient setting will be computed appropriately by CMS.
(Printed with permission of the ACR.)
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