Part B Insider (Multispecialty) Coding Alert

Plus: CPT overhauls lung scan codes.

Radiology coders are sure to cheer when they receive the new edition of the CPT manual, thanks to a host of new codes that should make life easier for many imaging practices.

For instance: You'll benefit from new code 74174 (Computed tomographic angiography, abdomen and pelvis, with contrast material[s], including noncontrast images, if performed, and image postprocessing). This serves as a combination of codes 74175 (CTA abdomen) and 72191 (CTA pelvis) for practices that perform this combination study.

As before, if you perform only a CTA abdomen, you'll report 74175; if you perform a CTA pelvis, look to 72191, and if you perform a CTA abdomen and pelvis, you'll bill new code 74174.

Gastro imaging: Also in the radiology section of CPT 2012, you'll find that CPT has eradicated hepatobiliary system imaging codes 78220-78223 and replaced them with the following new codes:

• 78226 -- Hepatobiliary system imaging, including gallbladder when present;
• 78227 --...with pharmacologic intervention, including quantitative measurement(s) when performed

Respiratory imaging: Rounding out the radiological changes, you'll find a vast overhaul of the respiratory imaging section, with codes 78584-78598 completely deleted, and code 78580 revised to say "Pulmonary perfusion imaging (eg, particulate). In place of the deleted codes, you'll find the following:

• 78579 -- Pulmonary ventilation imaging (eg, aerosol or gas)
• 78582 -- Pulmonary ventilation (eg, aerosol or gas) and perfusion imaging
• 78597 -- Quantitative differential pulmonary perfusion, including imaging when performed
• 78598 -- Quantitative differential pulmonary perfusion and ventilation (eg, aerosol or gas), including imaging when performed

The difference: Perfusion essentially tells the physician if there are any blood flow restrictions in the lungs. For perfusion, the provider injects protein particles tagged with a radioactive material that travel through the vascular system. The pulmonary circulatory system's small arterioles (small diameter blood vessels) trap the relatively large particles. The provider takes a series of images to assess lung perfusion (blood flow). Radioactivity won't be visible in the non-perfused areas, so the radiologist can spot where the blood flow problems are.

Recognize perfusion: The other type of lung scan is ventilation (described in the next section), so you have to be able to differentiate between perfusion and ventilation to choose the proper CPT code.

The quickest route is to look for the injection of the radioisotope, which is unique to perfusion. Ventilation studies require inhalation rather than injection.

Hint: Look for references to macroaggregated albumin in the report. This is the radiopharmaceutical injected for perfusion imaging. You may see it documented as Tc-99m-MAA, MAA, or Technetium MAA. The term "macrospheres" -- referencing the macroaggregated albumin -- also can narrow your choice to a perfusion study.