title: Renal imaging with 99Tc(m)-dextran.
abstract: Significant uptake and retention of 99Tc(m)-dextran (molecular weight: 81,000) in renal parenchyma was discovered during evaluation of its intravascular use. Renal SPET images confirmed this. This study was designed to evaluate 99Tc(m)-dextran as a renal cortex imaging agent. Stability of parenchymal retention was shown by insignificant outflow at 24 h and by frusemide intervention. Evaluation of the renal parameters of intravenous 99Tc(m)-dextran (n = 71 normal kidneys) and its comparison with 99Tc(m)-DTPA n = 10) and 99Tc(m)-DMSA(III) (n = 23) was undertaken. The early glomerular extraction phase of the renograms of 99Tc(m)-DTPA and 99Tc(m)-dextran appeared identical; parenchymal uptake of 99Tc(m)-dextran continued to increase and reached a near-plateau by 40-60 min. The mean cortex-to-background and cortex-to-liver ratios at 2 h with 99Tc(m)-dextran and 99Tc(m)-DMSA(III) were 14.9 and 9.2, and 16.0 and 8.9, respectively. The target-to-nontarget ratios were similar despite different absolute renal uptake values (12 vs 20% at 2 h) because of faster background clearance of 99Tc(m)-dextran. The mechanism of parenchymal retention of 99Tc(m)-dextran appears to be trapping at the endothelial-epithelial interphase of the glomerulus. Our initial experience suggests 99Tc(m)-dextran is a viable renal parenchyma imaging agent.
authors.affiliation: Department of Nuclear Medicine, Institute of Nuclear Medicine and Allied Sciences, Lucknow Marg, Delhi, India.
authors.forename: A
authors.initials: A
authors.lastname: Bhatnagar
authors.forename: A K
authors.initials: AK
authors.lastname: Singh
authors.forename: A
authors.initials: A
authors.lastname: Babbar
authors.forename: N L
authors.initials: NL
authors.lastname: Soni
authors.forename: T
authors.initials: T
authors.lastname: Singh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003911:Dextrans / Q000493:pharmacokinetics*; D005260:Female; D005665:Furosemide; D006801:Humans; D007275:Injections, Intravenous; D007672:Kidney Cortex / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism; D007674:Kidney Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D011933:Reagent Kits, Diagnostic; D012016:Reference Values; D004113:Succimer / Q000493:pharmacokinetics; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D016284:Technetium Tc 99m Pentetate / Q000493:pharmacokinetics; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D003911:Dextrans; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D011933:Reagent Kits, Diagnostic; C034146:technetium Tc 99m dextran; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D005665:Furosemide; D004113:Succimer; D016284:Technetium Tc 99m Pentetate