Measurement of splenic function with heat-damaged RBCs: effect of heating conditions: concise communication.

RBCs labeled with Cr-51 were heated in saline, and RBCs labeled with Tc-99m were heated in plasma or as packed cells. Blood clearances were then compared. Clearance for saline-heated cells was faster than for heated, packed cells, and much faster than for plasma-heated cells. RBCs heated in plasma for 20 min at 49.5 degrees C were insufficiently damaged for measurement of spleen function, but adequate spleen images were obtained in all patients, despite half-clearance times that varied from 14 min to over 90 min.