Splenic radionuclide scanning and sequestration of thermally altered erythrocytes in hepatosplenic sch istosomiasis.

Using heat-treated 51Cr tagged red cells radionuclide scanning of the spleen was performed in 17 patients suffering from hepatosplenic schistosomiasis. Furthermore, following the injection of the thermally damaged erythrocytes, the disappearance half time of radioactivity was calculated from splenic radioactivity build-up tracings. Out of the 17 bilharzial patients examined, 12 had disappearance half times shorter than the lowest limit obtained in normal subjects, denoting exaggerated splenic trapping of heat-treated red cells. Analysis of the results showed that the rate of trapping of heated erythrocytes was more rapid in patients presenting with bigger splenic enlargement, as well as in those having more marked anemia. This might be taken to indicate a possible link between the occurrence of anemia and the spleen in schistosomiasis. By radionuclide scanning, the bilharzial spleen was bigger than normal. In addition, the splenic shadow appeared to be either oval, triangular or kidney shaped. In 9 patients, the distribution of radioactivity was homogenous, with decrease in the density towards the periphery. In the remaining 8 cases, patchy distribution of radioactivity was observed. Mottling was more marked in the huge spleens as well as in the presence of severe anemia.

Radionuclide scanning of the spleen. Technical modification, normal variants and dimensions.

In order to cut down the time needed for the preparation of the thermally damaged erythrocytes, the effect of heat was combined with the use of a higher concentration of ACD. Heating of the 51Cr tagged red cells was performed in a water bath, at 50 degrees C for 15 minutes, in the presence of ACD in the ratio of one ml ACD for every 3 ml blood. Using this technique, the obtained splenic scans in 20 normal individuals were excellent in quality. In the posterior view, the spleen was oval with an oblique long axis in 65% of the cases and transverse long axis in another 15%. In the remaining 20% the spleen was globular. The average measurements of the spleen were 10.5 X 7,1 cm, with a circumference of 29.8 cm. By planimetry, the surface area of the spleen averaged (59 +/- 12.4) cm2 (Mean +/- 1 S.D.) In the lateral projection, the surface area of the splenic scan was larger by an average of 40% than the picture obtained through the posterior approach in all the six examined subjects.