RT Journal Article
SR Electronic
T1 Measurement of Metabolic Extraction of Tracers in the Lung Using a Multiple Indicator Dilution Technique
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 31
OP 37
VO 25
IS 1
A1 Javad Rahimian
A1 Edwin C. Glass
A1 Juan J. Touya
A1 S. Farooq Akber
A1 L. Stephen Graham
A1 Leslie R. Bennett
YR 1984
UL http://jnm.snmjournals.org/content/25/1/31.abstract
AB Selective pulmonary uptake of many natural and synthetic substances has been demonstrated by physiologists and pharmacologists using isolated perfused lung preparations or invasive techniques. It is difficult, however, to relate these laboratory studies to disease processes and to the study of problems encountered in a clinical environment. Our goal was to develop a noninvasive method for studying the pulmonary uptake of tracer substances using available radiotracers, gamma cameras, and computers that would give information similar, if not identical, to that from the invasive laboratory methods, and that could be applied in a clinical setting. The multiple-indicator dilution technique, modified for external counting, is well suited for such studies of pulmonary uptake of tracer substances. In this study, Tc-99m micro sulfur colloid (Tc-99m micro SC) was used as an intravascular reference tracer, N-isopropyl-p-[123I]iodoamphetamine (I-123 IMP) as a cellular test tracer amine, and In-111 DTPA as an extracellular tracer. Calculated first-pass lung uptakes of I-123 IMP and In-111 DTPA were 0.92 ± 0.04 and 0.17 ± 0.04, respectively, relative to the reference tracer. Using this approach, the first-pass pulmonary extraction of a variety of radiolabeled test tracers can be measured in a clinical environment in a variety of physiologic settings.