Radiology Coding Alert

Question: Which codes are appropriate if the radiologist performs both aerosol ventilation and perfusion lung scan for a patient with COPD? I can't find COPD in the ICD-9 index.Arkansas SubscriberAnswer: You should report only one unit of 78588 (Pulmonary perfusion imaging, particulate, with ventilation imaging, aerosol, one or multiple projections) to indicate both tests.The procedure involves 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).ICD-9: Your chronic obstructive pulmonary disease (COPD) diagnosis code will depend on the documentation. Per the ICD-9 official guidelines, "the conditions that comprise COPD are obstructive chronic bronchitis, subcategory 491.2, and emphysema, category 492" (http://www.cdc.gov/nchs/datawh/ftpserv/ftpicd9/icdguide07.pdf). You should report 491.21 (Obstructive chronic bronchitis; with [acute] exacerbation) for patients diagnosed with COPD who have had an exacerbation.Definition: "An acute exacerbation is a worsening or a decompensation of a chronic condition. An acute exacerbation is not equivalent to an infection superimposed on a chronic condition, though an exacerbation may be triggered by an infection," the guidelines state.Report 491.20 (Obstructive chronic bronchitis; without exacerbation) for patients diagnosed with COPD classified as obstructive bronchitis by the physician in the documentation/medical record, but without an exacerbation.When the COPD is not otherwise specified, report 496 (Chronic airway obstruction, not elsewhere classified). The ICD-9 official guidelines state that you should report this nonspecific code only when the medical record doesn't specify the COPD type.Note: Physicians may also order these nuclear medicine exams to diagnose pulmonary embolism (415.1X, Pulmonary embolism and infarction), but a CT with contrast is now more common for this purpose.