Regional myocardial perfusion assessed with generator-produced copper-62-PTSM and PET.
We have previously demonstrated that myocardial perfusion can be estimated accurately in experimental animals with the generator-produced positron-emitting tracer, 62Cu-pyruvaldehyde bis (N4-methylthio- semicarbazone)(62Cu-PTSM) and PET. This study evaluated the feasibility of quantifying regional myocardial blood flow using 62Cu-PTSM and PET in human subjects.


METHODS
Regional perfusion was estimated using a previously described and validated two-compartment model from dynamic PET scans obtained after an intravenous bolus of 62Cu-PTSM in 10 healthy volunteers and in 6 patients with coronary artery disease at rest: and in 9 of the volunteers and 4 of the patients after administration of dipyridamole intravenously. Flow estimates were compared with those obtained using H2(15)O.


RESULTS
Contrast was high between myocardium and blood or lung with 62Cu-PTSM, resulting in high-quality myocardial images. Liver uptake was also high. At flows of up to 1.5 ml/g/min, flow estimated with 62Cu-PTSM correlated closely with estimates obtained with H2(15)O (y = 0.71x .21, n = 169 regional comparisons, r = 0.66, p < 0.55), but this relationship was not maintained at higher flows.


CONCLUSIONS
The results demonstrate that quantification of myocardial perfusion with 62Cu-PTSM is feasible in human subjects but cannot be used to estimate hyperemic flows due most likely to the strong binding of the tracer to human serum albumin. Copper-62-PTSM congeners with less avidity for human albumin may prove more suitable for evaluation of hyperemic flows.
Herrero
P
P
Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Hartman
J J
JJ
Green
M A
MA
Anderson
C J
CJ
Welch
M J
MJ
Markham
J
J
Bergmann
S R
SR
D000328:Adult; D003300:Copper / Q000493:pharmacokinetics; D003301:Copper Radioisotopes; D003326:Coronary Circulation / Q000502:physiology; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D005240:Feasibility Studies; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D010104:Oxygen Radioisotopes; D011876:Radionuclide Generators; D012709:Serum Albumin / Q000378:metabolism; D013882:Thiosemicarbazones / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed; D014665:Vasodilator Agents
D003301:Copper Radioisotopes; D009942:Organometallic Compounds; D010104:Oxygen Radioisotopes; D012709:Serum Albumin; D013882:Thiosemicarbazones; D014665:Vasodilator Agents; C052629:copper pyruvaldehyde bis(N(4)-methylthiosemicarbazone) complex; D004176:Dipyridamole; D003300:Copper