Myocardial imaging with 99mTc-Tetrofosmin: Influence of post-stress acquisition time, regional radiotracer uptake, and wall motion abnormalities on the clinical result.
BACKGROUND
We previously demonstrated that early (15', T1) post-stress myocardial imaging with Tetrofosmin could be more accurate than standard acquisitions (45', T2) in identifying coronary artery disease.


RESULTS
To clarify this phenomenon, 120 subjects (age 61 +/- 10 years) with both T1 and T2 scans were divided into Group 1 (53/120 pts) with more ischemia at T1 vs T2 imaging (T1-T2SDS > or = 3); Group 2 (67/120 pts) with similar results (T1-T2SDS < or = 2). Myocardial areas were categorized as control nonischemic, ischemic, and scarred on the basis of perfusion/contraction properties and coronary anatomy. In each area, regional myocardial count statistic and semiquantitative wall motion/thickening values were obtained. Analysis of T1 and T2 post-stress myocardial counts demonstrated a significant Tetrofosmin wash-out rate that was higher in Group 1 control nonischemic regions (15 +/- 8% vs 13.6 +/- 9.6%, P < .02), significantly lower in Group 1 ischemic regions (7 +/- 10% vs 12.2 +/- 9.5%, P < .0001), and comparable between scarred areas of the two groups (P = NS). Delta post-stress wall thickening (T1-T2) was lower in Group 1 ischemic regions (-4.5 +/- 9.15% vs -1.90 +/- 7.0%, P < .001) and comparable in both control nonischemic and scarred areas of the two groups (P = NS).


CONCLUSIONS
The clinical result of Tetrofosmin gated-SPECT can be influenced by the post-stress acquisition time because of ischemic-induced regional wall thickening abnormalities and the existence of a differential radiotracer myocardial wash-out.
Giorgetti
Assuero
A
Monasterio Foundation, National Research Council/Tuscany Region, Via Moruzzi 1, 56124, Pisa, Italy. asso@ifc.cnr.it
Kusch
Annette
A
Casagranda
Mirta
M
Tagliavia
Irene D'Aragona
ID
Marzullo
Paolo
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D009206:Myocardium / Q000473:pathology*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin