Tuberc Respir Dis.  1990 Sep;37(3):268-277. 10.4046/trd.1990.37.3.268.

Ventilation-perfusion Lung Scintigraphy in Patients with Bronchial Asthma

• KMID: 2528482
• DOI: http://doi.org/10.4046/trd.1990.37.3.268

Abstract

Bronchial asthma is characterized by reversible airway obstruction and uneven ventilation. Uneven ventilation and abnormal gas exchange occur before other abnormalities of lung function become apparent. But the relationships between arterial blood gases or pulmonary functions and findings of the ventilation-perfusion lung scintigraphy in patients with bronchial asthma were not certain. We observed the patterns of ventilation and perfusion distribution by using ^99mTc-phytate radioa-erosol and ^99mTc-MAA, and their relationships to arterial blood gases and spirometric indices in 50 patients (16 women and 34 men) with bronchial asthma. the results were as foIIows; 1) The uneven distribution of ventilation were inversely correlated with vital capacity (VC, r=-0.489, p<0.01), forced vital capacity (FVC, r= - 0.451, p < 0.01), FEV₁ (r= - 0.545, p<0.01), FEV₁ / FVC (r= -0.411, p<0.02), and relatively weII correlated with PaCO₂ (r=0.4 45, p<0.02). 2) The central deposition of radioaerosol in ventilation scan were also inversely correlated with VC (r= -0.695, p<0.01), FVC (r= -0.722, p<0.01), FEV₁ (r= -0.753, p<0.01), FEV₁/FVC (= -0.490, p<0.01), and relatively weII correlated with PaCO₂ (r=0 .473, p<0.01). 3) The uneven distribution of perfusion were also inversely correlated with VC (r= - 0.343, p< 0.05), FVC (r=-0.380, p<0.05), FEV₁(r=-0.434, p<0.01), FEV₁/FVC (r=-0.478, p<0.01), but not cor. related with arterial blood gases. 4) The spirometric index mostly weII correlated with abnormal ventilation was the FEV₁. 5) Ventilation defects matched with perfusion defects. 6) The uneven distribution of ventilation and perfusion showed a tendency to increase during the asthmatic attack but to decrease during the recovery in 3 patients. 7) During the recovery, the deposition of radioaerosol disclosed a “dendritic" appearance rather than central deposition in the ventilation scan. Our data suggest that the ventiIation and perfusion lung scintigraphy may be useful tests for the diagnosis and the evaluation of therapeutic response in patients with bronchial asthma, especiaIIy during asymptomatic period.