Table of Contents

Basics of Lung Perfusion and Ventilation CPT codes

There are two components of lung function, ventilation and perfusion. Ventilation refers to the ability of air to reach all areas of the lung. The perfusion scan measures the blood supply through the lungs. A ventilation and perfusion scan is most often done to detect a pulmonary embolus (blood clot in the lungs). It is also used to detect abnormal circulation (shunts) in the blood vessels of the lungs (pulmonary vessels)

In medical coding, different procedure codes are assigned for reporting Lung perfusion and ventilation scan exam. CPT code 78579 is used only for ventilation imaging, while CPT code 78580 is used for Pulmonary perfusion imaging. When both ventilation and Perfusion scan is done, then we have to report CPT code 78582.

In respiratory physiology, the ventilation/perfusion ratio (V̇/Q̇ ratio or V/Q ratio) is a ratio used to assess the efficiency and adequacy of the matching of two variables: V̇ or V – ventilation – the air that reaches the alveoli. Q̇ or Q – perfusion – the blood that reaches the alveoli via the capillaries.

Before going ahead, let us check some coding information about outpatient exams.

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Description of CPT code 78579, 78580, 78582, 78597 & 78598

In ventilation scan, a gaseous radionuclide, such as xenon or technetium DTPA, contained in an aerosol is inhaled through a mouthpiece or mask. The patient inhales the aerosol taking as deep a breath as possible and then holds the breath as long as possible. Images are obtained during this scan and ventilation of lungs are evaluated.

Nuclear ventilation imaging of the lungs is designed to show the regional distribution of inspired air throughout the lung tissue and the uptake and clearance dynamics of the lungs. The patient is usually placed supine and breathes in a radioaerosol or gas through a tube that is attached to a nebulizer.

Once the aerosol or gas is inhaled, the radioactivity stays in the area where it was deposited long enough to take images with a camera that detects the gamma radiation being given off from the aerosol or gas in the air spaces. Increased central deposition occurs in severe obstructive airway disorders. Rapid clearance from the lungs reflects interstitial lung disease, such as in smokers, where systemic absorption rises due to increased alveolar capillary permeability.

Ventilation and perfusion imaging of the lungs is used to detect pulmonary embolisms and the percentage of total perfusion and ventilation attributable to each lung. Ventilation imaging of the lungs shows the regional distribution of inspired air throughout the lung tissue and the uptake and clearance dynamics of the lungs by having the patient inhale a radioaerosol or gas. Perfusion imaging uses an injection of radioactive albumin, which are particles too big to pass through the pulmonary capillary bed and accumulate there, mapping blood perfusion as they are strained out.

Standard perfusion imaging usually consists of eight planar images from different projections with the posterior oblique views being most important since they image the lower lobes, the most common site for pulmonary embolisms. The two types of images complement each other for diagnosis purposes. When the data for these studies are acquired on a digital computer, lung perfusion and ventilation can be quantitated for gradient comparisons and function differential calculations. CPT code 78597 is reported for pulmonary perfusion testing only. CPT code 78598 is reported for pulmonary perfusion and ventilation testing.

For perfusion scan, an intravenous catheter is placed and a radioactive tracer, such as technetium macro aggregated albumin (Tc99m-MAA), is injected and images are obtained for evaluation.

78579 – Pulmonary ventilation imaging (eg, aerosol or gas)

78580 – Pulmonary perfusion imaging (eg, particulate)

78582 – Pulmonary ventilation (eg, aerosol or gas) and perfusion imaging

For quantitative exam, we have separate procedure codes, as shown below. Quantitative differential pulmonary perfusion and ventilation studies compare and measure the accumulation of the radioactive tracer in different regions of the lung and/or compare and measure the accumulation of radioactive tracer in the lung and other regions of the body

78597 – Quantitative differential pulmonary perfusion, including imaging when performed

78598 – Quantitative differential pulmonary perfusion and ventilation (eg, aerosol or gas), including imaging when performed

To perform the ventilation component, a gaseous radionuclide, such as xenon or technetium DTPA, contained in an aerosol is inhaled through a mouthpiece or mask. The patient inhales the aerosol taking as deep a breath as possible and then holds the breath as long as possible. Scintographic images are obtained and ventilation of different lung regions is measured and then compared.

Supply and Equipment codes used with CPT code 78579, 78580, 78582, 78597 & 78598

SA048 pack, minimum multi-specialty visit
SB006 drape, non-sterile, sheet 40in x 60in
SB022 gloves, non-sterile
SB044 underpad 2ft x 3ft (Chux)
SC001 angiocatheter 14g-24g
SC012 heparin lock
SC029 needle, 18-27g
SC049 stop cock, 3-way
SC051 syringe 10-12ml
SG021 bandage, strip 0.75in x 3in (Bandaid)
SG050 gauze, non-sterile 2in x 2in
SH040 heparin lock flush soln
SH068 sodium chloride 0.9% inj bacteriostatic (30ml uou)
SJ053 swab-pad, alcohol
SM022 sanitizing cloth-wipe (surface, instruments, equipment)

ED019 computer workstation, nuclear medicine analysis-vi
ED020 computer workstation, nuclear pharmacy management
ED050 Technologist PACS workstation
ED053 Professional PACS Workstation
EQ343 Radioaerosol Administration System
ER001 Cobalt-57 Flood Source (47cm dia) (10 mCi)
ER026 dose calibration source vial set (Cs137, Co57, and
ER027 dose calibrator (Atomlab)
ER032 gamma camera system, single-dual head
ER053 radiation L-block tabletop shield
ER054 radiation survey meter
ER058 safe, storage, lead-lined