[Estimation of pulmonary intravascular and extravascular spaces by 99mTc-albumin lung distribution ratio and 201Tl lung uptake ratio].

In order to estimate the pulmonary extravascular and intravascular spaces, lung uptake ratio of 201Tl (L/T) and lung distribution ratio of 99mTc-albumin (H/T'), expressed as ratios of total counts of the bilateral lungs to the administered doses of the radionuclides, were obtained from the both scintigrams with 201Tl and 99mTc-albumin respectively, using a scintillation camera coupling to a minicomputer. Mean values of L/T and H/T' were 2.8 +/- 0.8% and 4.9 +/- 1.4% in the controls, 3.9 +/- 1.8% and 5.3 +/- 1.9% in heart diseases without left heart failure, and 7.0 +/- 2.2% and 7.1 +/- 2.9% in those with left heart failure, respectively. Ratios of L/T to H/T' in diffuse interstitial pneumonia and heart diseases, especially in cases with left heart failure were higher than those in controls. The values of H/T' and L/T were inversely proportional to cardiac output and cardiac index, and the values of L/T were directly proportional to pulmonary artery wedge pressure, but the discrepancies of the relationship between these values and some clinical findings including cardiac output, cardiac index, pulmonary artery wedge pressure and other findings of left heart failure, were observed in not a few cases. In the regional pulmonary areas, lung uptake of 201Tl was in parallel with pulmonary perfusion in many cases, but the discrepancies between them were demonstrated in some cases, too. These methods seem to be useful for the estimation of the pulmonary extravascular and extravascular spaces, and for the detection of dysfunction of the left ventricle.