Ratio of MRglu (OSEM/FBP) for Various OSEM Reconstruction Techniques
| Tissue | ROI | 2 × 12 | 4 × 16 | G5 | |
|---|---|---|---|---|---|
| 2 × 12 | 4 × 16 | ||||
| Myocardium | Short axis, template ROI | 1.11 | 1.09 | 1.08 | 1.05 |
| Axial slices, isocontour ROI | 1.09 | 1.15 | 1.02 | 1.02 | |
| Tumor | 2.5- to 5-cm diameter | 1.14 | — | 1.01 | — |
| Brain | Gray matter | 0.97 | 1.02 | 0.94 | 0.98 |
G5 = with smoothing.
Data are given for OSEM 2 × 12, 4 × 16 with and without 5-mm FWHM Gaussian smoothing of reconstructed image. Uncertainty of these ratios is 3% (1 SD) or less for brain and myocardium. For tumors, larger variation of this ratio was observed, as shown in Figure 6.