1993 年 57 巻 4 号 p. 291-298
The pulmonary blood flow in 84 patients with left to right cardiac shunts was preoperatively and postoperatively examined by scintigram with macroaggregates of &l;t99m>Tc-labeled human serum albumin. Lung biopsy was also performed in 28 patients. The regional pulmonary blood flow distribution curves obtained from perpendicular scintillation to the long axis of the right lung in the supine position were classified into 4 patterns (normal and types I to 3). The normal pattern displayed uniform distribution, however type I demonstrated a lack of upper corner in the curve. Type 2 showed 2 peaks (a lower peak in the upper and a higher peak in the lower part of the lung) with a dip between them. Finally only I peak in the lower part of the lung was manifest in type 3. The right Upper/Lower lung count ratio, R(U/L), expressed as the mean±standard deviation in each curve type was 0.82±0.12 (n=23), 0.71±0.11 (n=28), 0.6±0.08 (n=17) and 0.58±0.18 (n=16), respectively. The count ratios from the 3 abnormal types were statistically significant compared to the normal curve type (p<0.01). In addition, the type I and 2 curves were significant compared to type 3 (p<0.05-0.01). In patients under 3 years of age, lower R (U/L) count ratio expressed more severe pulmonary hypertension. Negative correlations were observed with the peak pulmonary/peak systemic pressure ratio, Pp/Ps, (r=-0.66, p<0.01) and with the pulmonary vascular resistance index, PVRI, (r=-0.45, p<0.01). However, these correlations disappeared in patients above age 3. The postoperative alteration of the curve type depended on the preoperative severity and was considered useful for follow-up. Seventy-five percent of type I patients changed to normal after I year. However, the more severe type 2 and 3 patients only demonstrated recovery to normal in 43% and 10% of the cases, respectively.
