Abstract:
99Tc
mNDBODC5 for intravenous injection was prepared. The labelling yield was 95.0%±0.52%. Sixteen New Zealand rabbits were involved and planar gamma imaging was performed at 10 timepoint after injection of
99Tc
mNDBODC5. The radioactivity channes of organs were calculated by regions of interest (ROI) analysis. The 16 rabbits were divided into 4 groups and were sacrificed at 30, 60, 120, and 180 min after injection respectively. The activity for all excised organs were measured by γwell counting for calculating radiouptake. Myocardial uptake for 99TcmNDBODC5 is high. Though myocardial uptake was lower than 99TcmMIBI, the liver clearance for
99Tc
mNDBODC5 was more rapid than that of
99Tc
mMIBI. As early as 30 min after injection,
99Tc
mNDBODC5 hearttoliver ratio is 0.98±0.52 versus 0.56±0.19 for
99Tc
mMIBI (P<0.01). At 60 min postinjection,
99Tc
mNDBODC5 hearttoliver ratio improved to the peak value (1.18±0.57), compared with 0.71±0.29 for
99Tc
mMIBI, P<0.01. After 60 min, the hearttoliver ratio of
99TcmNDBODC5 was keeping at a high level until 180 min.
99Tc
mNDBODC5 exhibited rapid lung clearance, similar to that of
99Tc
mMIBI. The biodistribution in the isolated organs demonstrated the same trend. The rapid
99Tc
mNDBODC5 liver clearance may allow the earlier imaging, and overcome the photon scatter from the liver with high activity which interfered the inferoapical wall in myocardial images.
99Tc
mNDBODC5 is a promising new myocardial perfusion imaging agent with superior biodistribution properties.