Reducing Formation of Suspected Tracer Microemboli During Preparation of ^99mTc-Tagged Heat-Damaged Red Blood Cells

The abnormal placement of splenic tissue is a matter of major clinical significance in situations where it may be mistaken for malignant or metastatic disease, as this can alter patient management or cause the patient to undergo unnecessary invasive procedures. Scintigraphy with ^99mTc-tagged heat-damaged red blood cells is a useful noninvasive method of identifying splenic tissue. However, the process of preparing and tagging the patient's blood may result in suspected microaggregate-related pulmonary foci after reinjection. We describe the reduction of these pulmonary foci seen on our initial scan with only 100 IU heparin coating in the blood drawing syringe, to 50% (3 of 6 scans) upon increasing heparin coating to 100 IU or 150 IU in the blood drawing and reinjection syringes, to 0% (0 of 5 scans) with 300 IU in each syringe.