Quantitative evaluation of regional blood flow in pulmonary sarcoidosis with bull's eye analysis

Abstract

Lung perfusion scintigraphy was performed in 23 patients with pulmonary sarcoidosis and in 11 normal volunteers. Bull's eye analysis was used to analyze regional pulmonary blood flow quantitatively. First, whole lung perfusion images were divided into three regions by three concentric circles. Then radial axes were projected from the center to define 36 x 10 degrees sectors. The counts for each sector were calculated and a Bull's eye image was displayed. The counts were compared with the lower limit of normal (mean - 2SD), and as the indices of reduction in perfusion, extent score (ES) and severity score (SS) were calculated. ES and SS showed significant reduction in perfusion 16 patients (70%) with sarcoidosis. In stage II sarcoidosis, both ES and SS were significantly higher than in stage I sarcoidosis (p less than 0.05). In comparison with the findings of transbronchial lung biopsy, both ES and SS had correlations with the degree of alveolitis and ES had a correlation with the degree of angiitis. Both ES and SS have no correlation with 67Ga scintigraphy findings. In comparison with clinical data, ES had a positive correlation with serum angiotensin-converting enzyme activity (p less than 0.05), and SS had a significant positive correlation with bronchoalveolar lavage fluid.CD+/CD8+ ratio (p less than 0.05). The Bull's eye analysis was considered useful for the quantitative evaluation of regional pulmonary blood flow in pulmonary sarcoidosis, and it was suggested that the mechanism of reduction in perfusion might be resulted mainly in its alveolitis and angiitis. Ventilation abnormality, which may happen prior to reduction in perfusion, may be an important factor of reduction in perfusion.