Pulmonary regional ventilation-perfusion relationships in chronic cardiopulmonary disorders. I. Radioactive rare gas method (Xe-133, Xe-135 and Kr-85 method).

Abstract

This is the study attempting to clarify quantitatively the regional disturbance of ventilation-perfusion relationships in pulmonary diseases. Measurements were made on 7 normal subjects, 16 cases with pulmonary parenchymal diseases and 4 cases with pulmonary vascular diseases. Perfusion and inhalation scintigrams were taken in sitting position and were divided into 9 horizontal zones in order to know relative values of regional pulmonary blood flow (Q) and alveolar ventilation (VA). Cardiac output and minute alveolar ventilation were also obtained at the same time. Using these data, absolute values of regional VA, Q and VA/Q of 9 zones were analyzed from the base to the apex of both lungs. In 7 normal subjects the average regional VA /Q ratio was 0.64 at the base and increasing 1.35 at the apex. In 20 patients the ratio ranged between 0 and 11.2, and even in the parts of parenchymal disorders the ratio was generally higher than normal since the decrease of regional perfusion was more remarkable than that of regional ventilation. Discussions were made on the usefulness as well as limitations of this scintiscanning method in approaching ventilation-perfusion unevenness topographically and quantitatively.