[Optimal protocol for 99mTc-tetrofosmin myocardial SPECT imaging with exercise or dipyridamole stress test and the characteristics of bullseye normal file].
To determine optimal protocol for 99mTc-tetrofosmin SPECT imaging, 30 normal volunteers underwent treadmill or dipyridamole stress test with 770 MBq of tetrofosmin injection. Anterior planar images were acquired every 10-15 minutes for calculating heart/liver ratio. SPECT images were also obtained every 30 minutes for generating Bullseye normal files. In analysis of spatial tracer distribution among normal files, myocardium in Bullseye plot was divided in 9 areas, where mean values of % tracer uptake were calculated and compared by analysis of variance (ANOVA). In those 9 areas, mean values of SD (SD mean) were also compared for predicting artificial blackout in the Bullseye plot among 3 standard normal files: dipyridamole-201Tl, dipyridamole-tetrofosmin (60 min post-injection), and treadmill-tetrofosmin (30 min post-injection). In planar image analysis, high initial uptake in the liver and its acceptable clearance were noted in dipyridamole stress test. Adequate heart/liver ratio was accomplished immediately after treadmill, but 40 minutes later after dipyridamole stress test. ANOVA analysis showed no statistical difference in the spatial % tracer uptake among normal files, irrespective of time after acquisition, data collection time, or difference of tracer. However, SD means in inferior and lateral area of treadmill-tetrofosmin file were significantly small compared to that of dipyridamole-201Tl normal file (p < 0.02 by ANOVA). Thus, we conclude that optimal timing for tetrofosmin SPECT imaging is immediately after treadmill, but at least 40 minutes after dipyridamole stress test. In addition, we should also keep in mind that unexpected blackout may appear in inferior and lateral area, when applying our normal files for reference.
Nakagawa
S
S
Department of Cardiology, Tokyo Saiseikai Central Hospital.
Kimura
M
M
Kurimura
K
K
Igarashi
A
A
Ooba
Y
Y
D000704:Analysis of Variance; D004176:Dipyridamole; D015444:Exercise; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D012016:Reference Values; D015899:Tomography, Emission-Computed, Single-Photon
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; C078700:technetium tc-99m tetrofosmin; D004176:Dipyridamole