Gelb et al. (A-25) conducted a study in which they explored the relationship between moderate to severe expiratory airflow limitation and the presence and extent of morphologic and CT scored emphysema in consecutively seen outpatients with chronic obstructive pulmonary disease. Among the data collected were the following measures of lung CT and pathology (PATH) for emphysema scoring:

CT Score PATH CT Score PATH 5 15 45 50 90 70 45 40 50 20 85 75 10 25 7 0 12 25 80 85 35 10 15 5 40 35 45 40 45 30 37 35 5 5 75 45 25 50 5 5 60 60 5 20 70 60 Source: Dr. Arthur F. Gelb. Used with permission.