Estimation of myocardial perfusion and viability using simultaneous 99mTc-tetrofosmin--FDG collimated SPECT.
This study was designed to elucidate the usefulness of crosstalk correction for dual-isotope simultaneous acquisition (DISA) with 99mTc-tetrofosmin and FDG in estimating myocardial perfusion and viability.


METHODS
Eighteen patients with coronary artery disease were studied. First, SPECT was performed with a low-energy high-resolution collimator after a single injection of 99mTc-tetrofosmin (single 99mTc-tetrofosmin). Second, PET and DISA with an ultra-high-energy collimator were performed after glucose loading and an injection of FDG. DISA was designed to operate with simultaneous 3-channel acquisition, and weighted scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak was performed by modification of an existing dual-window technique. The FDG SPECT images were compared with the images obtained by PET. Both crosstalk-corrected and uncorrected 99mTc-tetrofosmin images were generated and compared with the single 99mTc-tetrofosmin images.


RESULTS
Regional percentage uptake of FDG agreed well between DISA and PET. However, regional percentage uptake of 99mTc-tetrofosmin was generally higher on the uncorrected 99mTc-tetrofosmin images than on the single 99mTc-tetrofosmin images, especially in areas of low flow (percentage count of 99mTc-tetrofosmin > or = 50%). The crosstalk correction contributed to improving the agreement between regional percentage uptakes and significantly improved the detectability of myocardial perfusion-metabolism mismatching.


CONCLUSIONS
With 3-channel acquisition and weighted-scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak, DISA with 99mTc-tetrofosmin and FDG is feasible for assessing regional myocardial perfusion and viability.
Fukuchi
K
K
Department of Radiology, National Cardiovascular Center, Suita, Osaka, Japan.
Katafuchi
T
T
Fukushima
K
K
Shimotsu
Y
Y
Toba
M
M
Hayashida
K
K
Takamiya
M
M
Ishida
Y
Y
D000368:Aged; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D015902:Gamma Cameras; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D009206:Myocardium / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000493:pharmacokinetics; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012044:Regression Analysis; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C078700:technetium tc-99m tetrofosmin