Pulmonology Coding Alert

Distinguish perfusion scans by reading between the lines. Here's how.

Coding perfusion and ventilation scans of the lungs can be intimidating if you don't do it with care. If you let the technical details confuse you, you'd be risking inconsistencies, which could result in improper coding.

Overview: When a pulmonologist wants to know how well a patient is getting oxygen into their blood (and carbon dioxide out), she orders a V/Q test, which measures the ventilation/ perfusion ratio between the amount of fresh air brought into the alveoli in the lungs and the amount of blood flow past the alveoli in the lungs using scintigraphic imaging. In a perfusion study, the patient gets an intravenous injection of radioactive material into his bloodstream, and scintigraphy imaging will show if there are any parts of the lungs where the radioactive blood just cannot get to (due to some kind of plug in the bloodstream).

Similarly, a ventilation study allows a patient to inhale radioactivity, and scintigraphic imaging will show if there are any parts of the lungs where the radioactive gas just can't get to (due to some kind of plug in the lungs or bronchioles).

Confused yet? You can avoid putting a provider at compliance risk or at financial risk by following these 3-step guidelines.

Step 1: Identify Perfusion Study Without a Sweat

In order to report your claim properly, you will simply need to determine if radioactive isotopes were provided to the patient via just a blood stream injection (perfusion), or via inhalation either of a radioactive gas such as Xenon, or of oxygen that has been aerosolized with particles of a radioactive substance (ventilation). Just the same, it's possible that a nurse or medical staff performs both the injection and the inhalation.

Clue: To determine if a perfusion study was done, check the physician's report for any hint of perfusion lingo. Also look for language that indicates the injection of radioactive isotopes into the bloodstream, for example:

• Tc-99m-MAA
• Macroaggregated Albumin
• Technetium MAA
• Macrospheres
• Perfusion

Once you know you're dealing with a perfusion study, you can focus on a sole CPT code to assign: 78580 (Pulmonary perfusion imaging, particulate). A perfusion scan is one way of evaluating patients for lung volume reduction surgery (LVRS). The test sees if there are any parts of the lung that have low perfusion, says Kevin Carney, RN, at Temple University Hospital, Temple Pulmonary Center, Philadelphia.

Step 2: Let Keywords Guide Your Ventilation Study Coding

When you want to determine if the healthcare provider performed a ventilation study, you may see clear documentation, such as the given key word "ventilation." But that's not all. You will need to know if the patient inhaled a radioactive gas (generally Xenon), or if the patient actually inhaled oxygen that had been aerosolized with particles of a radioactive substance.

You'd be able to tell a gaseous radioactivity with a language that includes:

• Xenon
• Xenon gas
• Gaseous
• Xenon-133
• Xe 131
• Krypton
• Krypton gas
• Krypton-81
• Kr 81

Some language clues that relates to oxygen that has been aerosolized with radioactive particles include:

• DTPA
• Tc-99m
• Technetium DTPA
• Particulate
• Mist
• Aerosol
• Aerosolized

Coding ventilation study requires you to choose from five different codes that may describe the service: 78586 (Pulmonary ventilation imaging, aerosol; single projection), 78587 (...multiple projections [e.g., anterior, posterior, lateral views]), 78591 (Pulmonary ventilation imaging, gaseous, single breath, single projection), 78593 (Pulmonary ventilation imaging, gaseous, with rebreathing and washout with or without single breath; single projection), or 78594 (...multiple projections [e.g., anterior, posterior, lateral views]).

What is: A projection refers to the image of a threedimensional object on a plane, as in a radiograph.

Step 3: Select the Right Code Out of Combined Study

If there was just a single breath taken of this radioactive gas/ aerosolized oxygen, or if there was also rebreathing/washout with plain non-radioactive oxygen, tells you it might well be a combined perfusion/ventilation study.

Purpose: Single breath sees how well the radioactivity can get to all parts of the lungs, while rebreathing determines how long and how many breaths it takes for the patient to clear the radioactive material out of the lungs. As usual, keywords in your physician's report might indicate there was rebreathing/ washout. They are:

• Equilibrium
• EQ
• Wash-in
• Washout
• Rebreathing
• Air trapping
• Gas trapping
• Clearance

In this case, you'd have three code choices: 78584 (Pulmonary perfusion imaging, particulate, with ventilation; single breath), 78585 (...rebreathing and washout, with or without single breath), or 78588 (Pulmonary perfusion imaging, particulate, with ventilation imaging, aerosol, 1 or multiple projections).

Tricky: Code 78588 specifies aerosol, but 78584 and 78585 say ventilation without specifying aerosol or gaseous. Consider 78584 and 78585 specific to gaseous studies with perfusion, says Becki Garaud, CPC, CPC-E/M, RCC, compliance education and coding trainer for the University of Washington Physicians and Childrens University Medical Group Compliance Program.

Example: A 55-year-old postop patient has sudden onset pleuritic chest pain, dyspnea and hypoxia. Initial testing does not exclude pulmonary embolus, and the physician orders a V/Q scan.

Combined pulmonary imaging scans involve imaging a patient twice, "once after inhalation of a radioactive aerosol to determine pulmonary ventilation; and again after injection of a radioactive particulate to determine lung perfusion," according to the AMA's CPT Assistant (March 1999).