Procedure for red blood cell labelling with 99mTc-HMPAO. Methodology and quality control

Abstract We present here results on the labelling of red blood cells with 99m Tc-HMPAO as an alternative method to the usual in vitro technique. Anticoagulant agents, the labelling medium with plasma, and the lapse of time between 99m Tc-HMPAO preparation and labelling are the main factors which affect the efficiency of the procedure. A 93.9 ± 2.3% labelling yield was obtained with freshly prepared 99m Tc-HMPAO. In vitro (tracer elution of 4.3 ± 1.2% at 60 mins) and in vivo (percentage of plasma activity at 60 mins, 7.8 ± 2.8%) stability of the label, as well as image quality, qualify 99m Tc-HMPAO labelled red blood cells as a suitable agent for clinical use.