Computed tomography (CT) and computed tomographic angiography (CTA) are imaging studies that continue to see increases in volumes and are targeted by the payers for medical necessity and coverage. While it may seem that coding for these procedures is straightforward, there are some key considerations that should be acknowledged to ensure compliance billing practices.
The first critical issue to be reviewed is the order for the service. If you are billing for a CTA study, then it would be expected you have an order for a CTA study for that patient. Remember most commercial (non-Medicare) payers will require pre-certification (aka pre-authorization) of CT and CTA procedures. If the facility, or physician, submits a procedure code other than the one preapproved by the payer, then typically no reimbursement will be provided since it does not match their pre-approved information.
Now the trickier issue – should I code a CT or a CTA? The performed imaging study should match the ordered study and the radiologist’s dictation should clearly support what was performed. Challenges arise when the dictated report does not clearly include all of the required documentation to support the assignment of a CTA code.
CTA requires and includes 3D angiographic rendering. Clinical Examples in Radiology (Fall 2011) states, “Only when 3D is documented should the coder assign a computed tomographic angiography (CTA) code, as CTA requires 3D postprocessing.” A study that includes only 2D postprocessing should be coded as a CT scan rather than a CTA. In addition to the term 3D, other terms such as maximum intensity projection (MIP), shaded surface rendering, and volume rendering may also be used to describe 3D postprocessing. However, multiplanar reconstruction (MPR) is a 2D postprocessing technique, according to (Clinical Examples in Radiology (Fall 2013)). Clinical Examples in Radiology (Spring 2017) provides the following example of proper CTA documentation: “CT angiography of the [body area] was performed without IV contrast followed by IV contrast, including 3D post processing CTA image reconstruction.”
CTA is performed using intravenous contrast. The CTA codes are defined as “with contrast material(s), including noncontrast images, if performed.” This means if a noncontrast scan is performed prior to contrast administration, it is included in the CTA study and is not separately reportable. According to CP® Assistant (August 2011), “Although in many circumstances, noncontrast imaging is not required as a prelude to CT angiography, any noncontrast imaging performed during the same session – whether for localization or diagnostic purposes – should not be separately reported.” If intravenous contrast is not administered and 3D imaging is still performed, it is appropriate to report the non-contrast CT code specific to the anatomic site being studied, with either 76376 or 76377 for the 3D rendering, according to (Clinical Examples in Radiology (Spring 2020)
In most cases it is not appropriate to report a CT code together with a CTA code for the same body area. As mentioned earlier, the CTA code includes noncontrast images if performed. Also, there is some degree of overlap between CT and CTA, because data acquired during a CTA exam includes images of non-vascular structures (bones, soft tissues, etc.). These non-vascular structures must be eliminated from the images during postprocessing to create the images of the vessels.
According to Clinical Examples in Radiology (Summer 2008), performance of a CT and CTA on the same body area on the same day would be infrequent. It might occur, for example, when a CT scan shows a tumor in the pancreas, following which a CTA is performed. In order for both exams to be billed, the CTA must involve a “new data acquisition.” In other words, the patient must be scanned a second time and a new data set acquired. In this situation, both exams may be charged.
So, the bottom line is that in order to charge for both exams, there must be an order from the treating physician for both exams, both exams must be medically necessary, there must be two data sets acquired and both must be separately and completely documented.
Melody W. Mulaik, MSHS, CRA, RCC, RCC-IR, CPC, COC, FAHRA, is the president of Revenue Cycle and Coding Strategies Inc.