Sentence examples for scatter estimate from inspiring English sources
The bottom row gives the relative difference to the CTAC-based scatter estimate.
The scatter estimate was calculated for only the first two iterations, and the scattering was modelled only during forward projection.
This scatter estimate is then used to correct the next iteration for scatter (using an additive factor in iterative reconstruction).
However, since the annihilation photons may also be scattered by the hardware, the scatter estimate based on attenuation maps not including the hardware components may be inaccurate.
However, in our reconstructions, these negative counts could not occur because the TEW scatter estimate was included in the denominator of the OSEM formula.
Figure 2 Comparison of reconstructed FDG images using the scatter estimate provided by the vendor's SSS (left) and our MCS method (right).
Effect of inaccurate scatter estimates: Scatter estimation requires knowledge about the attenuation distribution.
Therefore, to investigate the effect of such inaccurate scatter estimates and the potential benefit when scatter estimation is based on attenuation maps including hardware components, we calculated and compared estimated scatter distributions corresponding to the uncorrected, xMLAA-, and CTAC-based attenuation maps.
Similarly, inaccuracies in the scatter estimates, e.g., obtained by neglecting the flexible hardware components during scatter estimation, were not found to have a significant effect on PET quantification.
However, we showed that the xMLAA-based scatter estimates were much more accurate than the scatter estimates obtained without considering hardware components (Fig. 11).
The impact of the different scatter estimates on PET quantification was also evaluated.
