913-116 Quantitative Comparison of Planar and SPECT Normal Databases of Thallium-201, Sestamibi, Tetrofosmin and Furifosmin

Abstract

For quantification of planar and SPECT myocardial perfusion imaging lower limits of normal (LLN) are generated for each specific radiotracer from normal subjects. It is unclear how LLN for TI-201 (TI), Tc-99m-Sestamibi (MB), Tc-99m-Tetrofosmin (TF) and Tc-99m-Furifosmin (FF) compare quantitatively Accordingly we performed quantitative comparison of exercise planar (P) and SPECT (SP) in normal subjects (< 3% likelihood CAD) with TI (P:26, SP:26); MB (P:20, SP:28); TF (P:27, SP:42) and FF (P:12, SP:13). LLN (mean – 2sd) were generated using 36-points circumferential count profiles of P views and SP short axis slices, Comparisons were made by unpaired t-tests of each matched data point of 2 radiotracers, Summed t-values > 2 (p < 0,051 represent a measure for point-to-point significant difference between LLN curves, The higher the value the greater the difference. The figure shows t-values for comparison of various tracers for P and SP: LLN of various tracers are significantly different from each other and greater for P than for SP. On P imaging differences between TI and Tc-99m agents were primarily at base and anterior wall, whereas on SP no pattern existed. Differences in P imaging may be due to marked effect of interpolative background subtraction, whereas back projection and filtering produces smaller random SP differences. Thus, LLN of various agents are markedly different for P but less for SP. Radiotracer-specific normal databases should be used for quantification of P and SP myocardial perfusion imaging.