Hemodynamic significance of increased lung uptake of thallium-201

To determine the hemodynamic significance of increased lung thallium-201 uptake, resting thallium images in 23 normal subjects and 90 patients with various cardiac diseases were reviewed. Significant thallium uptake in the lung was observed in 60 cases and was especially frequently in mitral valvular disease (19 of 19 cases) and in myocardial infarction (25 of 37 cases). Chest radiographs of most of these patients showed pulmonary congestion or edema (50 or 69 cases). Pulmonary wedge pressure was measured in 25 of these patients and was significantly higher than in those of normal thallium uptake in the lung. Assessment of lung thallium uptake at the time of myocardial imaging can be used as a noninvasive means for evaluation of pulmonary venous hypertension.