Kinetic characterization of a novel cationic (99m)Tc(I)-tricarbonyl complex, (99m)Tc-15C5-PNP, for myocardial perfusion imaging.
BACKGROUND
Intense liver uptake of (99m)Tc-sestamibi (MIBI) often interferes with visualization of myocardial perfusion in the inferior wall of the left ventricle. To develop improved myocardial perfusion agents, crown ether-containing dithiocarbamates and bisphosphines have been introduced in recent years. This study was designed to investigate the myocardial imaging properties and in vivo kinetics of a cationic (99m)Tc(I)-tricarbonyl complex, (99m)Tc-15C5-PNP, in comparison with MIBI.


METHODS
Dynamic cardiac images were acquired for 60 minutes after intravenous tracer injection using a small-animal SPECT system in healthy control rats and rats with myocardial infarcts. Myocardial and liver time-activity curves were generated for radiopharmaceutical kinetic analysis.


RESULTS
Good visualization of the left ventricular wall and perfusion defects could be achieved 20 minutes after (99m)Tc-15C5-PNP administration. (99m)Tc-15C5-PNP images in all hearts with infarcts showed perfusion defects, which were comparable to MIBI images. The kinetic curves plotted from 1 to 60 minutes demonstrated that (99m)Tc-15C5-PNP has a shorter washout half-life (6.4 ± 3.2 vs 124 ± 30.5 minutes, P < .01) in the liver, lower residual liver activity (14.5 ± 10.2% vs 36.5 ± 28.9%, P < .01), and higher heart/liver ratio than MIBI.


CONCLUSIONS
(99m)Tc-15C5-PNP has potential for rapid myocardial perfusion imaging with low liver uptake.
Liu
Zhonglin
Z
Department of Radiology, University of Arizona, P.O. Box 245067, Tucson, AZ 85724-5067, USA. zliu@radiology.arizona.edu
Chen
Liying
L
Liu
Shuang
S
Barber
Christy
C
Stevenson
Gail D
GD
Furenlid
Lars R
LR
Barrett
Harrison H
HH
Woolfenden
James M
JM
D000818:Animals; D008099:Liver / Q000378:metabolism; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009206:Myocardium / Q000378:metabolism; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D017256:Technetium Tc 99m Sestamibi; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi