Gastrointestinal scintigraphy using 99mTc- or 111In-labelled polymer beads

In order to establish normal and pathological stomach emptying characteristics by external measurement of a radioactive meal using a gamma camera and computer system, it is necessary for the radioactively labelled substance to have the same behaviour in the stomach as the ingested food. Resins containing chelating groups which enable binding to either reduced 99mTcO4- or 111In+3 were tested for their suitability as tracers mixed into solid food. The preparation of such styrene-divinyl-benzene resins containing either triethylenetetramine substituents or the fully carboxymethylated derivatives is discussed, as well as the procedures of labelling with either 99mTc-pertechnetate or 111In-chloride. An evaluation of the resins for gastrointestinal scintigraphy was performed on 3 chacma baboons and a male human volunteer with encouraging results.