[A study on the intrapulmonary kinetics of N-isopropyl-p-[I-123]-iodoamphetamine in patients with interstitial lung diseases--assessment of disease activity by dynamic scintigraphy and regional clearance curve].
Aiming at clinical application of N-isopropyl-p-[I-123]-iodoamphetamine (I-123 IMP) to lung diseases intrapulmonary kinetics of I-123 IMP was studied. Dynamic lung scintigraphy was performed after intravenous injection of 3 MBq I-123 IMP in six normal volunteers and twenty patients with interstitial lung diseases. Simultaneously data were acquired in a data processor with 60-sec intervals over the period of 60 min. Time-activity curves of two areas of each lung field were obtained to calculate k values by monoexponential fitting method. In patients with interstitial lung diseases k values were significantly decreased (p less than 0.001) (0.995 X 10(-2) +/- 0.26 X 10(-2) as compared with those (1.602 X 10(-2) +/- 0.24 X 10(-2) in normal volunteers. For the assessment of capillary blood volume in the lung Tc-99m Sn colloids (SN) were given i.v. before I-123 IMP in 16 patients. There was a high correlation between regional uptake ratio of I-123 IMP and Tc-99m Sn colloids (SN) both at 1 min (n = 64; r = 0.91) and 25 min (n = 64; r = 0.93) after injection. The k values of IMP clearance curves were correlative to diffusing capacity at rest for CO (DLCO) (r = 0.71, p less than 0.01), vital capacity (r = 0.53, p less than 0.05) and forced expiratory volume in 1 sec (r = 0.58, p less than 0.05). These results suggest that the lung clearance of I-123 IMP reflect the severity of the endothelial cell injury which cause decrease in the capillary blood volume in interstitial lung diseases. Dynamic lung scintigraphy with I-123 IMP should prove useful for monitoring disease activity of interstitial lung diseases providing a new parameters to assess a non-respiratory lung function.
Kumazaki
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D000328:Adult; D000368:Aged; D000662:Amphetamines / Q000493:pharmacokinetics; D001810:Blood Volume; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D020367:Iofetamine; D008168:Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011877:Radionuclide Imaging; D012129:Respiratory Function Tests; D012507:Sarcoidosis / Q000000981:diagnostic imaging
D000662:Amphetamines; D007457:Iodine Radioisotopes; D020367:Iofetamine