Renal imaging agents

Technetium-99m mertiatide (A/-[Ai-[A/-[(benzoylthio)acetyl]glycyl]glycine) is a renal imaging agent. It is excreted by the kidneys via active tubular secretion and glomerular filtration. The kit vial is reconstituted by using 740—3700 MBq (20—100 mCi) of Tc pertechnetate and boiling for 10 minutes. 

Radiopharmaceuticals are the preferred agents for the assessment of function, as opposed to structure. Renal imaging agents are classic examples in that sense, since they allow the monitoring of the imaging of glomerular filtration and tubular secretion functions of the kidneys. Currently there are two agents available one is Tc-DTPA of unknown structure, and the other one is the... 

The structure of [TcO(EDTA)] is illustrated in Fig. 2 and shows the Tc(V) to be seven-coordinate106. Stable, highly water soluble ions such as this are fairly readily eliminated by the kidneys and this structure may be relevant to the renal imaging agents employing EDTA and DTP A. 

Renal imaging agents which exhibit mixed behaviour may be useful in the study of kidney... 

Bingham JB, and Maisey MN (1978) An evaluation of the use of " Tc-dimercaptosuccinic acid (DMSA) as a static renal imaging agent. Br J Radiol 51 599-607 Clarke SEM, Lazarus CR, Wraight P, Sampson C, Maisey MN (1988) Pentavalent " Tc-DMSA, MIBG, and " Tc-MDP. An evaluation of three imaging techniques in patients with medullary carcinoma of the thyroid. J Nucl Med 29 33-38... 

Stoffel M, Jamar F, Van Nerom C, Verbruggen AM, Besse T, Squifflet JP, Beckers C (1996) Techne-tium-99m-L,L-ethylenedicysteine clearance and correlation with iodine-125 ort/zo-iodohippurate for determination of effective renal plasma flow. Eur J Nucl Med 23 365-370 Van Nerom CG, Bormans GM, De Roo MJ, Verbruggen AM (1993) First experience in healthy volunteers with technetium-99m L,L-ethylenedicysteine, a new renal imaging agent. Eur. J Nucl Med 20 738-746... 

Verbruggen AM, Nosco DL, Van Nerom CG, Bormans GM, Adriaens PJ, De Roo MJ (1992) Techne-tium-99m-L,L-ethylenedicysteine a renal imaging agent. I. Labeling and evaluation in animals. J Nucl Med 33 551-557... 

Technetium ( Tc ) mertiatide Diagnostic renal imaging agent... 

The purpose of a third kind of renal imaging agent is to measure the actual renal mass. To achieve this objective, the metal complex now needs to have different characteristics. Typically, it should have high affinity for the proteins localized in the tubular walls or be thermodynamically weak, allowing transmetalation into renal tubule proteins. Two commercially available Tc complexes fall in this class. The first one is the Tc(V) complex with dimercaptosuccinic acid (dmsa) and the other one is with glucoheptonate. The structure for the first one is quite well known, whereas for the second one a structure is assumed, cf. O Fig. 43.4. 

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