Radiology Coding Alert

Coding cardiovascular studies for nuclear medicine need not cause despair if you can tell an MPI study from a blood pool analysis.

In a recent teleconference presented by the Coding Institute titled "Strategies for Optimum Nuclear Medicine Coding and Reimbursement," Melody W. Mulaik, MSHS, CPC, RCC, president and co-founder of Coding Strategies Inc. in Atlanta, presented a series of questions that will make nuclear medicine coding easier.

Of the five main types of cardiovascular studies myocardial perfusion imaging (MPI), gated cardiac blood pool imaging, first pass cardiac imaging, myocardial infarction imaging, and right-to-left shunt evaluation the first two are by far the most common.

The Many Faces of Myocardial Perfusion Imaging

According to Mulaik, coders often express frustration at the difficulty of differentiating between perfusion and blood pool studies. Perfusion imaging involves analysis of the regional flow of blood and radionuclide within the heart muscle itself, while blood pool studies evaluate the heart's structural cavity.

MPI presents four codes to choose from: 78460 (Myocardial perfusion imaging; [planar] single study, at rest or stress [exercise and/or pharmacologic], with or without quantification); 78461 (... multiple studies, [planar] ...); 78464 (... tomographic [SPECT], single study at rest or stress [exercise and/or pharmacologic], with or without quantification); and 78465 (... tomographic [SPECT], multiple studies ...).

Planar imaging, nuclear medicine's most basic image, is the simplest technique, but SPECT, which is a multiplanar study, is the more common. Most often, Mulaik says, "you're going to see a SPECT study at rest and stress. 78465 is by far the most popular code that's used with MPI. But it's important to make sure that the documentation supports it."

Add-On Codes

Add-on codes are a key element to obtaining correct reimbursement for cardiovascular nuclear studies. Wall motion studies (+78478, Myocardial perfusion study with wall motion, qualitative or quantitative study) document the actual wall motion of the heart by tracking the movement of the left ventricle from systole to diastole. This add-on code may only be assigned with perfusion imaging CPT Codes 78460, 78461, 78464 and 78465.

Mulaik says you may sometimes see a wall motion study called by alternative language referring akenesis, dyskenesis or hypokenesis. She instructs coders to list wall motion in addition to the code for the primary procedure. For complete reimbursement, wall motion requires clear documentation from the physician.

The ejection fraction (+78480, Myocardial perfusion study with ejection fraction), which calculates how much blood the heart is pumping out to the rest of the body, always shows up in a patient chart as a percentage. Sometimes the doctor will just say it was normal, but ideally he will state the exact percentage in the radiology report. Sometimes you will see an LV (left ventricular) notation accompanying this study. Like wall motion studies, the ejection fraction add-on code may only be assigned with perfusion imaging CPT codes 78460, 78461, 78464 and 78465.

It is very common to bill all three codes on perfusion imaging. For example, Mulaik says, "if I did a SPECT study at rest and stress, with ejection fraction, with wall motion, I'm going to bill the 78465 (the study itself), 78480 (ejection fraction) and 78478 (wall motion)." Mulaik warns that some payers will not pay for add-on codes and can offer few words of comfort "this unfortunately is a trend that we are seeing in some areas of the country with more and more frequency."

In most cases, however, providers need not accept erroneous bundling of the add-on codes, says Gary Dorfman, MD, FACR, FSCVIR, president of Health Care Value Systems in North Kingstown, R.I. He reminds radiology practices to review their contracts, contest inappropriate bundling and find out their payers' policies on add-on codes.

Single or Multiple Studies

With all of the cardiovascular codes, but especially with MPI and blood pool imaging, alert coders should always ask whether the imaging was done at rest, or rest and stress. "If they performed a study at rest only," Mulaik says, it would just be a single study. "For the vast majority, it's a multiple study" (both rest and stress).

Single and multiple determination definitions aren't brain teasers, but when you're looking at spread-out visits, spotting the difference between multiple tests and multiple studies can get tricky. Keep in mind this simple rule: For multiple determinations, patients usually come in for a long time, or they come in twice. A patient encounter may last for an extended period of time or the patient may return a second time during the same day or over the course of two days to complete the study. Even if you see two unique sets of images or calculations at separate encounters, it is still the same study. For example, a chart will often contain words to this effect: "Imaging happened at 6 hrs, and 24 hrs later." This is still the same study, with one report, but it contains multiple tests.

MPI Scenario

Mulaik offered this example of MPI coding: No prior studies. The patient was given 40 milligrams of adenosine as a stress agent and 8.0 mCi of Tc-99m Cardiolite injected for stress. 30.0 mCi of Tc-99m Cardiolites are used for rest. Indications: chest pain and assess myocardium. No evidence of stress-induced left ventricular enlargement. There is a perfusion abnormality at the posterior inferior wall seen on stress and rest and the appearance consistent with a posterior inferior wall infarction. No evidence of ischemia on the basis of this SPECT study and no additional perfusion abnormality. Wall motion is normal. Left ventricular ejection fraction is 54 percent.

Mulaik advises coding this case as follows: 78465, 78480 and 78478. The language that indicates that both stress and rest studies were performed clearly indicates a multiple MPI study, while references to the ejection fraction and wall motion justify the add-on codes.

Blood Pool Imaging Options

The perfusion scan examines blood flow into the heart while searching for blockages or other abnormalities. However, the blood pool scan evaluates the structure of the heart, usually the left ventricule. The basic blood pool imaging scan involves extracting red blood cells from the body, labeling the blood cells with radioactive material and returning them to the cardiovascular system for imaging. Usually, ventricular function is the object of this study.

Blood pool imaging presents you with five codes to choose from: 78472 (Cardiac blood pool imaging, gated equilibrium; planar, single study at rest or stress [exercise and/or pharmacologic] ... with or without additional quantitative processing), 78473 (... multiple studies ...), 78481 (first pass technique; single study ...) and 78483 (... multiple studies ...), and 78494 (... SPECT ).

Of these codes, the most frequently used is 78472, also known as an MUGA scan. It's called a "gated" study because it takes images that are synchronized with an EKG. An MUGA scan can be done at rest or stress, or both. MUGA scans do not have any commonly used add-on codes because they are all-inclusive studies, Mulaik says. She adds that while the SPECT technique occurs most frequently in the MPI line-up, with blood pool imaging it is not common.

Blood Pool Scenario

Mulaik shared this example with teleconference participants: The patient's red blood cells were labeled using 30.5 mCi of 99m Technetium pertechnetate and pyrophosphate by the modified in vivo method. Using computer acquisition and the EKG R-wave as a physiologic marker, anterior, left anterior oblique, left lateral, and posterior oblique views were obtained. The study was assessed visually and an ejection fraction calculated using standard computer algorithms. There is normal left ventricular wall motion within an ejection fraction calculated at 58%, which is within normal limits.

Mulaik advises coding 78472 in this case. Initially, one might be confused by the EKG reference and wonder whether it is a gated or a perfusion study. Mulaik says the key to identifying this study are phrases that show the structure was evaluated, thus indicating an MUGA scan with a single study. Remember that the ejection fraction is included in the blood pool imaging study.