Radiology Coding Alert

Question: I am confused about which code to assign for CT views of TM (temporomandibular) joints. Should I use 70486 or 70450?

Vermont Subscriber

Answer: Although both codes describe CTs performed on areas of the head (70486, computerized axial tomography, maxillofacial area; without contrast material or 70450, computerized axial tomography, head or brain; without contrast material) TMJs are a part of the maxillofacial area and thus should be reported with 70486. Protocols for 70450 generally do not provide adequate evaluation of the TM joints.

If the evaluation includes contrast, 70487 should be assigned. In addition, if the study was done without contrast followed by contrast, 70488 should be reported. In some cases, the radiologist will provide additional reconstruction images, and code 76375 (coronal, sagittal, multiplanar, oblique, 3-dimensional and/or holographic reconstruction of computerized tomography, magnetic resonance imaging, or other tomographic modality) may be billed as well.

In addition, the TM joints also might be imaged by plain films, arthrography, complex motion planar tomography and MRI.

If plain films are used, consider codes 70328 (radiologic examination, temporomandibular joint, open and closed mouth; unilateral) and 70330 ( bilateral). These describe specific coned-down views that are taken as separate studies or in addition to any Panorex (orthopantogram) or dental views. However, merely including the TM joints in the Panorex examination does not entitle a practice to code for the TM joint examination in addition to the Panorex study.

The arthrogram codes for contrast injection of the joint are 21116 (injection procedure for temporomandibular joint arthrography) to describe the injection procedure and 70332 (temporomandibular joint arthrography, radiological supervision and interpretation) to describe the S&I services. These codes are unilateral and include all preliminary plain films. If cine or video imaging is also performed, it is coded with add-on code 76125 (cineradiography to complement routine examination [list separately in addition to code for primary procedure]).

Complex motion planar tomography is rarely performed because CT and MRI have gained broader acceptance and are readily available. When it is used, 76101 (radiologic examination, complex motion [i.e., hypercycloidal] body section [e.g., mastoid polytomography], other than with urography; unilateral) may be used to describe examination of one side of the jaw and 76102 ( bilateral) for both sides. Again, these codes are not to be used to describe Panorex or orthopantogram studies. Finally, MRI studies of the TM joints should be coded as 70336 (magnetic resonance [e.g., proton] imaging, temporomandibular joint[s]).

You Be the Coder and Reader Questions were answered by Donna Richmond, CPC, radiology coding specialist with Acadiana Computer Systems Inc., a medical billing management company based in Lafayette, La., that serves more than 200 radiologists, pathologists and anesthesiologists.