Clinical and experimental studies on the mechanism of abnormal accumulation in lung scanning with 123I-IMP.
To investigate the intrapulmonary kinetics of N-isopropyl-p-I-123-iodoamphetamine (123I-IMP), lung scanning with 123I-IMP was performed in patients with various lung disorders. Compared with the normal lung field, abnormal accumulation of 123I-IMP was detected in all patients in delayed imaging performed 24 h after 123I-IMP injection. These sites were within areas of absent or reduced perfusion observed by pulmonary perfusion scanning using 99Tcm-macroaggregated albumin (99Tcm-MAA). A similar phenomenon was seen in additional experiments in rabbits with regional pulmonary arterial hypoperfusion resulting from a balloon catheter-induced bronchial occlusion. 123I-IMP accumulation in areas where 99Tcm-MAA images are absent or decreased may be explained by the ability of 123I-IMP to penetrate significantly narrowed microvascular beds with reduced perfusion. Our clinical and experimental results indicate that pulmonary arterial perfusion, particularly hypoperfusion, influence the pulmonary kinetics of 123I-IMP. This compound is a potentially useful non-particulate agent for the assessment of pulmonary arterial perfusion.
Suga
K
K
Department of Radiology, Yamaguchi University School of Medicine, Japan.
Ariyoshi
I
I
Nakanishi
T
T
Utsumi
H
H
Yamada
N
N
D000368:Aged; D000662:Amphetamines / Q000493:pharmacokinetics; D000818:Animals; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D020367:Iofetamine; D008168:Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation / Q000502:physiology*; D011817:Rabbits; D011877:Radionuclide Imaging; D013668:Technetium Tc 99m Aggregated Albumin / Q000493:pharmacokinetics
D000662:Amphetamines; D007457:Iodine Radioisotopes; D013668:Technetium Tc 99m Aggregated Albumin; D020367:Iofetamine