[Usefulness of 99mTc-DTPA-HSA scintigraphy in the diagnosis of protein losing enteropathy--comparison with 99mTc-HSA].

We evaluated the usefulness of 99mTc-diethylene-triamine-pentaacetic acid human serum albumin scintigraphy (FTPA-HSA) in the diagnosis of protein losing enteropathy in 3 cases of inflammatory bowel diseases in comparison with 99mTc-human serum albumin scintigraphy (HSA). The results were as follows: 1. DTPA-HSA demonstrated the colonic accumulation earlier than that of HSA. 2. Hepatic flexure and splenic flexure are not observed clearly, because of marked renal uptake in HSA. On the other hand, they are observed in DTPA-HSA. Hepatic uptake is rather stronger in DTPA-HSA. In conclusion, DTPA-HSA is one of the easiest and most useful methods in the diagnosis of protein losing enteropathy.

[Evaluation of clinical usefulness of 99mTc-GSA, a functional hepatic imaging agent--correlation with per-rectal portal scintigraphy].

Liver scintigraphy using 99mTc-GSA, which binds specifically to the asialoglycoprotein receptors on the surface of the hepatocytes, was performed in 41 patients with chronic liver disease (11 chronic hepatitis cases and 30 liver cirrhosis) to investigate the correlations between the images and the various liver function tests. Two liver functional indexes, HH15 for plasma clearance of 99mTc-GSA and LHL15 for liver accumulation of 99mTc-GSA, showed significant differences between the chronic hepatitis group and the decompensated liver cirrhosis group. These indexes also showed significant correlations with the liver function tests such as serum albumin level and prothrombin time. HH15 and LHL15 correlated with the per-rectal portal shunt index obtained in 10 patients by 99mTcO4- per-rectal portal scintigraphy. These results suggest that HH15 and LHL15 have value as new liver functional indexes.

Studies of quality control of 99mTc-labelled macroaggregated albumin--Part 1. Aggregation of non-mercaptalbumin and its conformation.

The aggregative condition of albumin was investigated using bovine serum albumin (BSA) as a model for quality control of 99mTc-macroaggregated albumin (99mTc-MAA). Uniformalized aggregates were obtained from the oxidized non-mercapt-type of BSA by heating. The size of the aggregates was affected by the pH and the types of buffer solutions used as well as the concentrations of albumin and buffers. The beta form structure of the albumin was more stable on heating and this may contribute to its aggregation. Aggregation of oxidized non-mercaptalbumin afforded a portion of smaller sized particles in MAA, this being an inappropriate factor for scintiscanning of lungs. Our results suggest that it is necessary to remove oxidized type albumin from human serum albumin as the starting material, in order to prepare MAA with a uniform and larger particle size.

Abnormal Tc-99m MAA accumulation.

Image findings are described in two patients who received radiochemically impure Tc-99m MAA radiopharmaceutical preparations. The cases are completely separate and show clinically the presence of hydrolyzed-reduced technetium (TcO2) in a radiopharmaceutical product.

Quality control of commercial 99mTc-human albumin kits.

The quality of a number of commercial human albumin kits used at Danish hospitals for preparation of 99mTc-labelled human serum albumin has been investigated by column chromatography and HPLC. In general, the radiochemical purity was found to be low (75% or less). In some cases with a poor radiochemical purity, the main radiochemical impurity, 99mTc-labelled tin colloid, amounted to 29% or more. A large molar tin to albumin ratio seems to lead to a low radiochemical purity and it is suggested that products with a high content of stannous chloride may be more correctly termed 99mTc-albumin/tin-colloid kits.