Lung scanning after intravenous administration of macroaggregated iodinated I 131 serum albumin has been used to study the regional pulmonary circulation in 62 patients with pulmonary emphysema. The major finding was that 95% of the patients had well-defined areas of decreased pulmonary arterial blood flow. In the majority of the cases, the chest roentgenogram alone was inadequate for demonstrating these localized changes. The scanning method was helpful in differentiating obstructive emphysema from less serious lung disease such as asthma and bronchitis. It was also useful in the determination of the desirability of surgery and in follow-up evaluation.
Lopez-Majano V, Tow DE, Wagner HN. Regional Distribution of Pulmonary Arterial Blood Flow in Emphysema. JAMA. 1966;197(2):81-84. doi:10.1001/jama.1966.03110020069024