[Hemodynamic significance of diffuse lung uptake of 201Tl in heart diseases]

Clinical significance of diffuse lung uptake of 201Tl was studied in 244 cases of various heart diseases. The grade of lung uptake of 201Tl was assessed by total lung uptake ratio (L/T), maximal lung uptake ratio (Max/T), lung to myocardium or mediastinum counts ratio (M/H or M/Med) and visual grade. L/T, Max/T, M/H and M/Med were directly correlated with pulmonary arterial pressure (PCW), and inversely correlated with cardiac output (CO) and cardiac index (CI). Among them, L/T was the best index to assess PCW, that was correlated with PCW (r = 0.65), CO (r = -0.53) and CI (r = -0.45). The visual grade of 201Tl lung uptake was correlated with L/T, and the increased lung uptake was associated with a higher PCW and a lower CO as well as a lower CI. Diffuse increased lung uptake of 201Tl was observed in 29 of 41 cases (70.7%) with myocardial infarction, 25 of 29 cases (86.2%) with mitral valvular diseases and 9 of 10 cases (90.0%) with combined valvular diseases, in addition, in most cases with left heart failure and cases of NYHA 3 and 4, but that was not rarely observed in cases of NYHA 2 and without left heart failure. In heart diseases, 201Tl myocardial scintigraphy seems to be valuable for detection of left heart failure including pulmonary congestion and interstitial pulmonary edema. Total lung uptake ratio (L/T) may be useful for estimation of PCW, and the visual grade of 201Tl lung uptake may be applicable as routine index for grading of lung uptake of 201Tl.