Technetium complexes imaging agents

Hepatobiliary agents technetium complexes, 984 Hepatobiliary system diagnostic imaging techniques technetium complexes, 989 Heptanal... 

Technetium ( Tc) radiopharmaceuticals such as (12.126) function as good myocardial imaging agents. Iron complexes of phosphorylated mono- and disaccharides will function as contrast agents in the MRI of the gastrointestinal tract [13]. 

Certain neutral technetium complexes can be used to image cerebral perfusion (Fig. 4). Those in Figure 4a and 4b have been approved for clinical use. Two other complexes (Fig. 4c and 4d) were tested in early clinical trials, but were not developed further. An effective cerebral perfusion agent must first cross the blood brain barrier and then be retained for the period necessary for image acquisition. Tc-bicisate is retained owing to a stereospecific hydrolysis in brain tissue of one of the ester groups to form the anionic complex TcO(ECD) , which does not cross the barrier. This mechanism of retention is termed metaboHc trapping. 

Technetium and rhenium coordination chemistry has actively developed in order to design materials as potential radiopharmaceuticals diagnostic imaging agents for technetium and potential therapeutic reagents based on rhenium. Continuous efforts are still applied to find efficient chelating systems for the [MO]3+ cores (M=Tc, Re). Thus several complexes with monodentate and... 

Technetium-labeled peptides and proteins have been investigated as potential thrombus-imaging agents. Complex 70, which combines 99mTc with the tripeptide motif Arg-Gly-Asp, binds GP Iib/IIIa recep-... 

An alternative approach to cationic myocardial imaging agents has been the development of neutral seven-coordinate Tc(III) complexes based on 1,2-dioxime ligands (dioximeH2) with one end capped by a boronic acid derivative (19, 253). These complexes are generally referred to as BATOs (boronic acid adducts of technetium dioximes) and have the general structure [TcX(dioximeH)2(dioxime)BR ] (X = Cl, Br R = alkyl) shown in 18. 

---