Usually, we instruct coders that if three-dimensional (3D) reconstruction of images is not described in the medical report, it is appropriate to code for a CT study and not a CTA study. This situation most often arises when physicians dictate notes following a CT of the chest for pulmonary embolism. Often physicians identify such a study as a CTA because during the study they are looking at vessels, but such a study is not really a CTA for coding purposes. When coding a CTA of the abdominal aorta with runoffs (code 75635), if the coder does not see a dictation specifying that a 3D postprocessing technique was used, should the coder code for a CT of the abdomen with contrast, a CT of the right leg with contrast, and a CT of the left leg with contrast? The 3D requirement for a CTA study when coding abdomen with runoff creates an issue if the physician does not document a 3D postprocessing technique.


If a 3D reconstruction of images is not appropriately documented in the medical report, a CTA study should not be reported. Though it would be “accurate” to report a CT of the abdomen, with contrast material study (code 74160), and a CT of each (right and left) lower extremity with contrast material (code 73701) with the correct modifier (modifier 50 or RT and LT), this could be judged to be “unbundling” the more comprehensive code. Thus, it is highly recommended that coders specifically ask the physician whether the 3D reconstruction of images was performed. If it was performed, then the physician should amend the report so that the coding can be reported appropriately to match the study performed.

This question was answered in our CT/MR Coder. For more hot topics relating to radiology services, please visit our store or call us at 1.800.252.1578, ext. 2.


CPT® copyright 2021 American Medical Association (AMA). All rights reserved.

Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use. The AMA does not directly or indirectly practice medicine or dispense medical services. The AMA assumes no liability for data contained or not contained herein.

CPT is a registered trademark of the American Medical Association.